Chapter 8: Lifespan Development of Human Potential

Learning Objectives

  • Describe how Piaget’s overarching principles of assimilation, accommodation, and schema development can serve to integrate the cumulative interactive effects of heredity and experience
  • Describe the tasks Piaget developed to study acquisition of conservation of number, mass, and liquid volume
  • Relate adaptive learning principles to Baumrind’s parental styles and Kohlberg’s stages of moral thinking

Fetal and Infant Development

Nature/Nurture and The Development of Human Potential

Since the scientific revolution, we have acquired considerable information about the most mysterious and wonderful phenomenon on earth, life itself. The progression of knowledge regarding the mechanisms of heredity including genes, chromosomes, and DNA has recently culminated in the mapping of the human genome. We are on the cusp of discovering what is genetically unique about the human being and perhaps, what is unique about our biological potential. This knowledge, however, will not be sufficient to determine our potential as individuals or as a species. As described in Chapter 7, the pace of scientific discovery and technological advancement is accelerating with no limit in sight. Kurzweil has made the seemingly impossible prediction that in the not too distant future humans will become immortal! Unless things change dramatically, immortality will not occur for the Nukak. Tragically, extinction appears the more likely fate. “It is the best of times. It is the worst of times” (Dickens, 1859). Never has the human species been in a better position to consider the meaning of life. Never has our species possessed such power to create or destroy.

The following are the first three articles from the United Nations General Assembly Universal Declaration of Human Rights (December, 1948):

Article 1.

  • All human beings are born free and equal in dignity and rights. They are endowed with reason and conscience and should act towards one another in a spirit of brotherhood.

Article 2.

  • Everyone is entitled to all the rights and freedoms set forth in this Declaration, without distinction of any kind, such as race, color, sex, language, religion, political or other opinion, national or social origin, property, birth or other status. Furthermore, no distinction shall be made on the basis of the political, jurisdictional or international status of the country or territory to which a person belongs, whether it be independent, trust, non-self-governing or under any other limitation of sovereignty.

Article 3.

  • Everyone has the right to life, liberty and security of person.

Americans will recognize these sentiments as being consistent with Thomas Jefferson’s most famous words from the Declaration of Independence: “We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty, and the Pursuit of Happiness.” The United Nations would apply these same ideals to the rest of the world. In order to achieve these noble objectives it is essential and strategic to focus our attention on children.

Figures 8.1 and 8.2 Amazonian rainforest children.

Brazil and Peru border on the Amazon. The photographs above, are of Ashaninka children in the Brazilan rainforest and Peruvian mainland children in school. I think you would agree, they might as well be on opposite sides of the world. The Ashaninka children are living similar to the ways their ancestors lived for thousands of years. Their environment is almost entirely natural. The Peruvian children’s environment was created by humans and includes laptop computers. These stark environmental differences enable us to appreciate Wechsler’s emphasis upon the adaptive and multi-faceted nature of human intelligence. The Ashaninka children must acquire the knowledge and skills accrued over thousands of years by previous generations of their tribe in order to survive. Peruvian children’s survival needs are met. They have the opportunity to explore the digitized accumulated knowledge of all the humans who have ever lived! A test to determine “intelligence” for one of these children would have to take their environmental conditions into consideration. Neither child could survive in the other’s world. The opportunities for the Ashaninka and Peruvian children to achieve their potential were determined by factors beyond their control at birth; where they were born and who their parents were. In this chapter, we will consider how nature and nurture interact to influence the course of human development from conception to adulthood.

Fetal Development

We are playing pretend. Congratulations! You have graduated, are romantically involved with a significant other, and expecting a child. The video below portrays the timeline for growth of a human fetus, be it in the rainforest or a city. During the first two months, the embryo consists of the layers of cells from which all organs and body parts will eventually develop. At three months, the fetus is about three inches long and weighs about an ounce. At four months, it is about five inches long and five ounces; the hardened skeleton is starting to form. At five months, the fetus reaches about ten inches in length and by six months, it weighs approximately one and a half pounds. At seven months, the fetus is about 15 inches in length and weighs about three pounds. The average birth statistics, after 39 weeks of pregnancy for children born in developed countries, are a length of 19 inches and weight of seven and a half pounds. Newborns vary considerably, even when taken to full term.

Problems are least likely to develop during pregnancy for mothers between 16 and 35 years of age. Under modern conditions, the mother’s health and lifestyle can have a significant effect on the fetus; diseases can be transmitted through the placenta. Substance abuse (drugs or alcohol) or smoking can result in premature birth, lower birth weight, and greater risk of birth defects, miscarriages, or stillbirths. The mother’s diet can also affect the fetus: a lack of iron can produce anemia; a lack of calcium can affect the formation of teeth and bones; a lack of protein can reduce size and increase the likelihood of cognitive deficits.

Infant Development

Once again, congratulations! You are the proud parent of a healthy infant. The term “infant” is derived from the Latin word for “speechless.” It is generally applied to children up till three years of age although they typically start to speak earlier. Sometimes this period is sub-divided with separate “newborn” (between birth and one month) and “toddler” (between one and three years) stages. As we will see in the next chapter, some of your baby’s personality will be influenced by heredity. Since we are playing pretend, you get to choose whether your child is a girl or a boy and you can choose whether she/he is active and curious or quiet and relatively passive. Your new job is to insure achievement of the goals expressed in the UN Declaration of Human Rights. You want to make sure your bundle of joy eats, survives and does well in school.

Let’s start with eating. Breastfeeding is generally considered to be healthier for the child than bottle feeding (Gartner et al., 2005). As described in Chapter 5, infants are born with rooting and sucking reflexes, facilitating the nursing process for mother and child. After birth, the mother’s breasts swell as they fill with milk. Nursing reduces the swelling, providing a sense of relief along with other enjoyable feelings stemming from holding and nurturing one’s baby. For breast feeding to occur, the infant needs to grasp and hold onto its mother. In the same way that infants possess reflexes facilitating eating, they possess reflexes facilitating grabbing and holding (Schott & Rosser, 2003). If something is placed in an infant’s palm, a strong grasping reflex occurs. Should the infant sense a sudden loss of support, the Moro reflex occurs; the child first spreads its hands and then restores them to a holding position. Usually, between four and six months of age, it is possible to begin the weaning process, transitioning from liquid to solid foods. When the child’s baby teeth start to appear, usually around ten to twelve months of age, it is possible to introduce soft finger-sized foods.

This early nursing experience was considered crucial to establishing the important role of the mother. It was thought the mother became a conditioned reinforcer through classical conditioning by being paired with food. Research conducted with other species suggested that other factors besides feeding were important. Harry Harlow (1958), studying rhesus monkeys, was the first to demonstrate the important role of touch in infant development (see also Field, 2002). Harlow, using a controversial procedure, reared the monkeys in isolation from their mothers. He constructed two types of “surrogate mother” dolls. One had a wire cylinder for a body and the other was covered with soft terrycloth.

In order to measure the degree of preference for the dolls, Harlow used a procedure similar to the one to assess self-control in pigeons described in Chapter 1. You may recall that the pigeons had to choose between a small, immediate reward, and a larger, delayed reward. Preference was measured by the percentage of times the pigeon pecked the associated keys. Harlow measured the amount of time monkeys spent with the two types of “surrogate mothers.” He found that when hungry, the monkeys went to the doll with the bottle. At other times, the monkeys had a strong preference for the terrycloth doll. The terrycloth doll also served as a secure “home base” from which the monkey would explore novel items or return to when afraid. In the absence of the cloth doll, the monkey frequently cowered and sucked its thumb. In its presence, the monkey would usually cling to the cloth doll initially and then explore the new stimulus. If a fearful stimulus was presented (e.g., a teddy bear that made a loud sound), the monkey would often run and cling to its “mother” before working up the courage to once again explore the environment (Harlow, 1958).

You might be thinking Harlow’s research is interesting but questioning whether the findings relate to human children. This is an external validity issue and an empirical question. Mary Ainsworth developed the Strange Situation procedure to study attachment and exploratory behavior in children between 12 and 18 months of age (Ainsworth & Bell, 1970; Ainsworth, Blehar, Waters, & Wall 1978). The children were observed playing, with and without their mother present, while strangers walked in and out of the room according to the protocol described in the following video.

Separation anxiety was often observed when the caregiver (usually the mother) left the room. Stranger anxiety might be displayed toward the unknown adult. The infant’s exploratory behavior, as well as its behavior when being reunited with the caregiver, was also assessed. Ainsworth and Bell (1970) divided the children into Secure (70% of their sample), Insecure-Ambivalent (15%), and Insecure-Avoidant (15%) attachment styles based on their performance during the different episodes.

  • The Secure attachment style applied to children displaying low levels of anxiety and avoidance. They played with toys, explored the environment, and interacted with strangers when the caregiver was present. A secure infant might be upset and cry when the caregiver left the room but would appear happy when she returned. The child was still considered secure even if he/she refused to interact with the stranger when the caregiver was not present.
  • The Insecure-Ambivalent attachment style applied to children displaying inconsistent emotionality. They were resistant to exploration and strangers, even when the caretaker was present. These children became severely upset when the caretaker left the room but did not seem overly happy when she returned.
  • The Insecure-Avoidant attachment style applied to children who did not appear emotionally attached to the caregiver. They did not appear upset when she left the room or happy when she returned. These children appeared passive no matter who was present.

In longitudinal studies, individuals are studied over extended periods of time. Correlations between Strange Situation infant attachment styles and the quantity and quality of subsequent peer relationships have been found in major longitudinal studies (National Institute of Child Health and Human Development Study of Early Child Care 1991-1995, 1996-1999, 2000-2004, 2005-2008); Minnesota Study of Risk and Adaptation from Birth to Adulthood (Sroufe, Egeland, Carlson, & Collins, 2009)). Secure children have more friends, enjoy more positive relationships, and are more likely to become leaders than insecure children. Insecure-ambivalent children are frequently anxious and unsuccessful in seeking friends. Insecure-avoidant children may become aggressive, thereby discouraging friendships.

Consistent with Harlow’s research findings with monkeys, Ainsworth & Bell (1970) felt that different infant attachment styles were the result of different caregiver (usually maternal) characteristics:

  • Warm and consistently responsive caregiving (often involving holding and touching) was correlated with the secure attachment style.
  • Inconsistent and unemotional caregiving was associated with the insecure-ambivalent style.
  • Unresponsive caregivers, who frequently ignored the child, were associated with the insecure-avoidant style.

Parenting Styles

Can you remember how your parents treated and influenced you at different stages of your life? Do you wish to become a parent? If so, what type of parent do you wish to become? Contemporary parenting styles have been categorized on the dimensions of demandingness and responsiveness (Baumrind, 1968, 1971; Maccoby & Martin, 1983). Demanding parents specify clear rules of conduct and require their children to comply. Responsive parents are affectionate and sensitive to their children’s needs and feelings. he following video describes the four parenting styles resulting from different combinations of high and low demandingness and responsiveness.

We may consider the implications of the learning principles described in Chapters 5 and 6 for these different parenting styles. Uninvolved, indifferent parents (low demandingness, low responsiveness) do not specify codes of conduct or respond to their children’s needs. If parents do not provide rules and/or consequences, the children will most likely be influenced by others (e.g., siblings, other adults, and eventually other children). From the perspective of the parents, This may result in the acquisition of undesirable behaviors.

Permissive, indulgent parents (low demandingness, high responsiveness) do not specify codes of conduct but are affectionate and responsive. They provide “unconditional positive regard” (Rogers, 1957), eliminating the contingency between desired behavior and consequence. We saw in Chapter 5, that the absence of a contingency between responding and consequences can result in learned helplessness. Non-contingent appetitive consequences (e.g., praise, gifts, etc.) can result in “spoiling” and a sense of entitlement. This could create problems for the children in other contexts (e.g., school, playgrounds) when others place demands and react differently to their behavior.

Authoritarian parents (high demandingness, low responsiveness) specify strict codes of conduct in a non-responsive manner. If the children ask for reasons, they may reply “because I say so!” In their parents’ absence, the children would seek other sources of authority.

Authoritative parents (high demandingness, high responsiveness) specify strict codes of conduct within a context of warmth and sensitivity to the children’s needs. They are likely to provide reasons for their codes of conduct, listen to their children’s perspective, and sometimes negotiate alternative codes. Authoritative parenting is most likely to result in secure attachment between parent and child.

Infant Skill Development

Now that you have thought about what type of parent you would like to become, you are most likely to concentrate on survival-related behaviors during the first years of your pretend child’s life. As we have seen, your child is equipped with nursing and grasping reflexes that facilitate an attached, dependent relationship with a caregiver. As a parent, you will begin walking the difficult tightrope balancing the need to nourish and protect your child with the need to foster independence. Early on, your child is immobile and her/his behavior seems sporadic and perhaps random. You might wonder if voluntary control learning (i.e., instrumental conditioning) is possible.

In a classic program of research, Carolyn Rovee-Collier (Rovee and Rovee, 1969) studied learning and memory in very young infants using a mobile suspended over their crib. A ribbon from the mobile could be attached to the infant’s leg. An active kicking motion would cause the colorful attachments to move. A reversal design (see Chapter 1) was employed in which the baseline frequency of kicking was assessed without the leg attached to the mobile, followed by a phase in which it was attached, and then a return to the detached baseline condition. The frequency of kicking in infants as young as eight weeks old, increased dramatically during the middle phase relative to the initial and subsequent baseline conditions. This is an early indication of the intrinsic motivation provided by controlling one’s environment.

Child Development


Whether a child grows up in the rainforest or a city, its thumb, tongue, and cortex will facilitate its adapting to its environment. That combination of physical characteristics has enabled us to survive as a species under a vast range of human conditions. During the first year, infants learn to use the forefinger and thumb to form the precision grip, permitting the grasping and manipulation of objects. As soon as children are sitting up they often enjoy solitary play. In the rainforest, children are given sticks and stones to manipulate. Favored toys for children growing up in contemporary homes include blocks of different shapes. Gradually, infants learn the futility of trying to put round blocks in square holes. Besides shapes, blocks are also excellent devices for teaching colors and even letters of the alphabet. As they develop, children may experiment by piling blocks on top of each other and creating different structures. Blocks can even eventually help children learn the “ABC”s.

Maturation refers to those developmental processes that occur as the result of aging. Your child will grow and its body proportions will change with age. Its head will become proportionally smaller and its limbs proportionally larger. As different parts of the body develop, new behaviors become possible.

Fundamental to adaptation and independence is walking on one’s own. Whether growing up in the rainforest or a large city, the child must sit up before crawling and stand before walking (see video). As a concerned parent, you will be interested in assisting your child achieve their continually increasing potential. The figure indicates the significant ranges children display in the ages at which they first demonstrate each behavior. Keep such individual differences in mind so that you do not become overly concerned if your infant appears a little slow in acquiring their first baby steps or other essential skills.

In addition to walking, there are other survival-related skills children must acquire during early infancy. They must learn to use their hands to eat, reach for, grasp, and manipulate objects. Gradually, children must learn to communicate with their caregivers using gestures and eventually language. Favorite games of infants include pointing to the parts of the face and peek-a-boo.

Humans are social animals born dependent on others; the course of their development will be significantly influenced by their interpersonal skills. Children must learn to interact with other family members as well as strangers, including other children.

The noted Russian psychologist, Lev Vygotsky (1962, 1978), described child development as the transition from socially shared activities to internalized processes. Through interactions with parents and other adults within a community, the child acquires speech. The child speaks out loud during the language acquisition phase. Eventually, speech is internalized (i.e., becomes silent) and serves as the basis for thought and action. Happy birthday! Your pretend baby will soon be celebrating her/his first birthday. You are eager to help your child along its way to achieving their potential. You would like her/him to walk and come to you when requested to do so. Teaching your child is essentially a problem-solving exercise as described in the previous chapter. How does your child behave now? How would you like your cild to behave in the future? What do you need to do to develop this behavior? Vygotsky proposed that a “zone of proximal development” existed, whereby teaching should only commence when it is certain the child is ready. We will assume your child is ready once standing without support and responding appropriately to a few words.

Vygotsky also introduced the term “scaffolding” to refer to effective adult support when teaching a child. At one year of age, you will not be able to rely entirely on language to teach walking. In Chapter 5, we described the shaping, prompting, and fading teaching techniques. Shaping is a scaffolding technique that continuously relies upon Vygotsky’s concept of a zone of proximal development. You start with a behavior already in the child’s repertoire and proceed only when the child is ready for the next step. Prompting and fading are also scaffolding techniques that can facilitate and speed up the learning process. You could teach your child to walk using shaping, prompting, and fading similar to the process described in Chapter 5 to train a dog to roll over. Unlike teaching a dog, however, it is not necessary (nor a good idea) to use food as a reinforcer. Recalling the distinction between extrinsic and intrinsic rewards from the previous chapter, your child will probably find covering ground and moving faster intrinsically motivating. You can establish feedback and praise as conditioned reinforcers by pairing success with words describing the accomplishment as well as words of affection. Remember the control learning ABC’s when starting out. When standing, say “Come to me” (an antecedent) while softly holding your child and trying to get her/him to take an initial step (a behavior). As the child moves, you could say “You are walking. What a big boy/girl” (a consequence). Once the child starts moving slightly when you say “Come to me”, you can release your grip a little. This would proceed until the child takes an initial step without your assistance. Now you could request “Come to me” while kneeling or standing a little further away and holding out your arms. You can close your arms and hug the child when he/she reaches you. By proceeding “step by step” in this fashion, your child will eventually come to you from any location upon request. Once walking, you could use the same procedures to request that the child bring you different objects. In addition to being a fun bonding and vocabulary development exercise, this process includes all sorts of benefits. For example, you can teach, “Please bring me my slippers, newspaper, TV remote”, etc. I don’t suggest trying “Bring me my coffee” for a while though.

Your child’s motor and cognitive abilities will continue to improve and expand during the second year. Imitation of the behaviors of other adults and older children will become more frequent. At the end of the first year, you will probably try to teach your child to attend to you and stop what they are doing when you say the word “No.” You may recall that this has the benefit of reducing the need to use physical punishment. Unfortunately, this may be an instance of “be careful what you wish for.” Teaching the word “no” may seem like a great success at the time, but eventually prove to be a two-edged sword. Don’t be surprised if, as your child starts the “terrible twos”, she/he says “No” every time you request something. Probably toward the end of your child’s second year, unlike parents in the rainforest, you and your significant other will try to teach control of a natural biological function; excretion of waste materials in liquid and solid form. In the rainforest, the Nukak child, who similar to your child, learned to walk during the first year, will be shown where to walk (or move a little faster when necessary) when “nature calls.” In your home, and as preparation for visiting the homes of others as well as nursery or pre-school, you will show your child where and how to “go potty.” Most likely, your child will say “No!” Once again, you may be wondering how to proceed with this latest exercise in problem solving. Vygotsky’s concepts again provide helpful guidance. You first need to determine whether your child is ready for toilet training (i.e., the zone of proximal development) and then determine the most appropriate teaching procedures (i.e., scaffolding).

There are many recommended “recipes” for toilet training available on Google and YouTube. How do you decide which to implement? Fortunately, there are empirically based assessment and teaching strategies. In Chapter 2, we saw that conducting an experiment in which an independent variable is manipulated is the only way to determine cause and effect. In this instance, we need to search the research literature to see if there is an experiment demonstrating the effectiveness of a toilet training procedure. Nathan Azrin was the 1975 recipient of the American Psychological Association Award for Distinguished Contributions for Applications in Psychology. What is startling and impressive about Azrin’s body of research is the consistent experimental demonstration of success of his intervention procedures with some of the most serious and intractable behavioral problems. These include his classic token economy procedures with chronic adult schizophrenics (Ayllon and Azrin, 1968), community reinforcement procedures with problem alcohol abusers (Hunt and Azrin, 1973), and social reinforcement procedures for individuals experiencing long-standing difficulties finding a job (Jones and Azrin, 1973). In addition, Azrin wrote the best-selling (and still available) Toilet Training in Less than a Day (Azrin and Foxx, 1974) based on prior successful research results (Azrin & Foxx, 1971; Foxx and Azrin, 1973).

Unlike walking, toilet training involves establishing a lengthy sequence of unrelated behaviors. It would be a time-consuming and painstaking task requiring extreme patience and skill to teach this sequence using the shaping, prompting, and fading procedures. Azrin and Foxx (1974) suggest waiting until your child is at least 20 months old before assessing whether she/he is ready to begin toilet training (i.e., has reached the zone of proximal development). Prior to then, it is unlikely that your child will have acquired the observational learning and language skills necessary to use indirect learning procedures. Before beginning you should insure your child is able to sit up, walk, imitate, know the names of and point to different body parts, remove and replace underwear, follow simple instructions, sense the need to go to the bathroom, and stay dry for at least two hours (Azrin and Foxx, 1974, 43-45).

Once these pre-requisite skills have been acquired, you are ready to proceed. Their process is based on the premise that the best way to learn something is to try to teach it to someone else. This will require having a doll which appears to wet. In this way your child can “teach dolly to go potty.” You start by pretending to give the doll a drink and telling your child that the doll has to go to the bathroom. Your child should then be shown how to remove the doll’s diaper, seat it on the potty, wait for it to “urinate” and then praise the doll for going to the potty (see Azrin and Foxx, 1974, 58-85 for detailed instructions).

Language and the Human Condition

Toilet training is perhaps the earliest example of the advantage of using language to teach a child. The acquisition of speech enables the transition to Piaget’s preoperational stage of cognitive development. The early structuralists considered sensations, images, and emotions to be the basic elements comprising conscious experience. The child is now able to symbolically represent these elements (i.e., its internal and external environment) with words. Vygotsky emphasizes the transition from talking out loud to talking to oneself. We use words to represent objects (nouns), actions (verbs), characteristics of objects and actions (adjectives and adverbs), and people (pronouns). Much of our thinking, including planning and problem-solving, consists of covert speech. Little by little, over the course of our lives, we describe our concepts and schemas with words as we develop elaborate narratives for understanding ourselves and our worlds.

All known human cultures speak. As quoted by Skinner (1986) in Chapter 6, it is perhaps the part of our genetic potential most responsible for our achievements as a species. Infants typically show signs of understanding speech at about six months but do not start speaking before one year of age. We described the importance of vocabulary size to success in school in Chapter 6 (Anderson and Freebody, 1986). Hart and Risley (2004) refer to these findings as “The Early Catastrophe: The 30 Million Word Gap by Age 3” (see video below). It has been estimated that disadvantaged children enter school with a vocabulary of 5,000 words in comparison to their more advantaged peers who average 20,000 (Moats, 1999). Research has shown a strong relationship between the vocabulary of first-graders and their subsequent reading comprehension scores (Cunningham & Stanovich, 1997; Scarborough, 2001). Findings indicate that Pre-K and kindergarten intervention efforts designed to improve vocabulary have been successful for middle- and upper-income at-risk children, but unfortunately, not thus far for lower-income children (Marulis & Neuman, 2010).

Preparing Children to Be Hunter-Gatherers

The portion of the Amazonian rain forest inhabited by the Nukak, consisting almost entirely of marshes and wetlands, does not support a permanent lifestyle based upon domestication of plants and animals (Politis, 2007). There are, however, abundant edible non-domesticated plant, fruit, and vegetable species and some edible animals (e.g., several species of monkeys, peccaries, tortoises, birds, ducks, and fish). The Nukak are one of the few remaining cultures continuing to practice the nomadic hunter/gatherer lifestyle characteristic of the earliest members of our species. They travel in bands comprised of approximately five nuclear families with a median of 20-30 individuals. Temporary shelters designed for stays of about four days are crafted from posts, tree branches, and leaves to form a camp. Furnishings include hammocks for sleeping and a hearth for cooking.

The Nukak, living day to day, have maintained a similar lifestyle for more than 10,000 years. They lack familiarity with government, property, or money. The Nukak do not have a concept of the future and their past history is limited to a few generations. In order to survive under very challenging conditions, the Nukak had to acquire the knowledge and skills to protect themselves from the elements and predators. They had to learn to forage and prepare a non-poisonous, nutritionally adequate diet.

Daily excursions from the camp are almost always led by an adult male, and many are limited to males. Most of the activities are related to hunting, fishing, and collecting foods (fruits, vegetables, honey, etc.). These trips also involve collecting resources such as cane for blowpipes, leaves for roofs, bark and vines for cords. Since their shelters have such low population densities, trips can involve searches for potential mates among other bands. Females often take part in local foraging trips, but most of their time is spent near the shelters caring for young children and preparing food. Time is frequently taken out during the day for men and women to pass on survival skills from generation to generation. Having to dedicate most of the day to survival needs and child care leaves precious little time for the Nukak to address the interpersonal and self-actualization needs higher on Maslow’s pyramid.

The Nukak have faced the same environmental demands and parents have transmitted the same survival skills from generation to generation for millennia. The Nukak essentially have two stages of development, childhood and adulthood. Piaget’s first two stages of cognitive development apply to Nukak children as well as those growing up in cities. They will start to speak at approximately the same age and their parents will take advantage of speech when teaching them. Nukak children’s toys usually consist of scaled down versions of survival tools. They participate in foraging, hunting, and food preparation as soon as they are physically able.

Preparing Children for School

The Nukak’s childhood contrasts with the extensive schooling required to create a common knowledge base and prepare children in technologically advanced cultures for ever-changing vocations. Many countries have compulsory primary and secondary education in order to address these goals. Thus, in addition to teaching a culture’s code of conduct, parents in these countries need to prepare their children to attend school.

Time is flying by and your pretend child is about to celebrate her/his third birthday. Congratulations, it is the end of the terrible twos! It is at this time that the life path for children growing up in the rainforest and city will diverge significantly to adapt to their different environmental demands. In order to adapt to the rainforest, the Nukak child will be taught gender appropriate hunter-gatherer skills. During the next two years you will help your child acquire many concepts and skills which are prerequisites for success in school. You will teach the names of colors, letters of the alphabet, numbers, and telling time. Gradually, his/her vocabulary will expand, sentences become more grammatical, use of imagination in telling stories and engaging in fantasy play increase, and interactions with other children become more cooperative. Conversations will increase in length and become more adult like in being targeted to the listener.

In 1998, the International Reading Association (IRA) and the National Association for the Education of Young Children (NAEYC) issued a research-based position statement regarding the teaching of reading and writing. Included in their statement were recommendations regarding what children, caretakers, and teachers can do at different ages to teach these skills. During the preschool years, it was recommended that parents and family members do the following:

  • Talk with children, engage them in conversation, give names of things, show interest in what a child says
  • Read and reread stories with predictable texts to children
  • Encourage children to recount experiences and describe ideas and events that are important to them
  • Visit the library regularly
  • Provide opportunities for children to draw and print, using markers, crayons, and pencils (IRA and NAEYC, 1998)

School represents a different “world” for children with its own set of adaptive requirements. Parents play an important role in preparing their children for school. The authoritative style characterized by high demandingness and high responsiveness has been shown to result in better school performance than the authoritarian style (Pratt, Green, MacVicar, & Bountrogianni, 1992; Hokoda & Fincham, 1995). In school, teachers, rather than parents, are the ones establishing standards and administering consequences. The dimensions of demandingness and responsiveness may be applied to teaching as well as parenting styles. Teachers may hold high or low standards for their students. They may be personable and warm in their classroom interactions or distant and detached. As with parenting, authoritative teaching styles result in better academic and social performance than authoritarian styles (Walker, 2008).

The School Years

Congratulations! Your pretend child is off to kindergarten. For perhaps the first time in your child’s life, you and she/he will endure the emotional process of extended separation. You and your child’s teacher will hopefully engage in a collaborative process designed to identify zones of proximal development and implement appropriate scaffolding techniques. During kindergarten the IRA and NAEYC recommend that parents and family members:

  • Daily read and reread narrative and informational stories to children
  • Encourage children’s attempts at reading and writing
  • Allow children to participate in activities that involve writing and reading (for example cooking, making grocery lists)
  • Play games that involve specific directions (such as Simon says”)
  • Have conversations with children during mealtimes and throughout the day

Your pretend child is getting older. Nature and nurture are interacting to result in a unique individual with likes/ dislikes, interests/ disinterests, ways of coping, and range of emotions. Some changes are obviously continuous. Your child is gradually getting taller (although there will be a spurt later on). We have seen that even a characteristic so obviously influenced by genes as height, is impacted upon by environmental factors such as nutrition and illness. The child’s vocabulary is similarly undergoing incremental growth and we start to observe apparent changes in reasoning, approaching and solving problems, and communicating with you and others.

In Chapter 7, we saw how the ability of chimpanzees to solve two-choice visual discrimination problems improved gradually over the course of 300 problems. At the end, the chimp appeared to solve the problems in a qualitatively different manner. Rather than observing gradual improvement across the first six trials of each new problem, the chimp would jump from chance to perfect performance on the second trial (Harlow, 1949). One might conclude, it transitioned from an “incremental learning stage” to a “hypothesis-testing stage” of development. The name of the stage is descriptive of the performance, not explanatory. The explanation lies in the history of exposure to examples of the same type of problem. Although heredity and environment interact gradually and incrementally, sometimes the behavioral effect appears to constitute a qualitative change in the individual. The ability to comprehend language and speak result from physical development of the infant’s brain and speech organs, improved ability to imitate, and continual exposure to vocalizations.

Theories of Development

Piaget’s Stage Theory of Cognitive Development

Jean Piaget, a Swiss psychologist, proposed an influential theory of cognitive development from birth through adulthood (Piaget, 1928; 1952; 1962; Piaget & Inhelder, 1973). Piaget was an example of a stage theorist. Stage theorists describe human development as a fixed sequence of capabilities resulting in qualitatively different ways of responding to the world. The first two stages last from infancy through preschool and the early grades. Piaget describes cognitive development as the continual modification (i.e., accommodation) of schemas based on the incorporation (i.e., assimilation) of new knowledge. From approximately birth to two years the child is preverbal, learning the relationships between sensory stimuli (e.g., visual and auditory stimuli, etc.) and movement. Piaget’s overarching principles of assimilation, accommodation, and schema development can serve to integrate the cumulative interactive effects of heredity and experience as the child ages and advances through the different stages.

Interacting with a child that speaks is fundamentally different than interacting with a non-verbal child. Piaget’s distinction between non-verbal (sensorimotor) and verbal (pre-operational) stages seems appropriate. We need to be careful, however, in how we interpret the meaning of a stage of development. It is one thing to describe the child as behaving as though being in a particular stage and a very different thing to offer the stage as an explanation for behavior. You might recognize this as another example of a pseudo-explanation. Why does the child speak? Because she/he is in the pre-operational stage. How do you know she/he is in the pre-operational stage? Because she/he speaks.

In Chapter 7, we saw how the ability of chimpanzees to solve two-choice visual discrimination problems improved gradually over the course of 300 problems. At the end, the chimp appeared to solve the problems in a qualitatively different manner. Rather than observing gradual improvement across the first six trials of each new problem, the chimp would jump from chance to perfect performance on the second trial (Harlow, 1949). One might conclude, it transitioned from an “incremental learning stage” to a “hypothesis-testing stage” of development. The name of the stage is descriptive of the performance, not explanatory. The explanation lies in the history of exposure to examples of the same type of problem. Although heredity and environment interact gradually and incrementally, sometimes the behavioral effect appears to constitute a qualitative change in the individual. The ability to comprehend language and speak result from physical development of the infant’s brain and speech organs, improved ability to imitate, and continual exposure to vocalizations.

The newborn is able to sense the environment and emit a variety of responses. Whether in the rainforest or at home, as the newborn turns its head it will observe that some objects are stationary and others move. Some of the moving objects make sounds and others do not. Some of the objects feel soft and cuddly whereas others are hard. One of the soft moving objects makes sounds and sometimes approaches and holds the infant while placing its lips near something soft. This soft object can be sucked, resulting in the availability of a substance which can be tasted and smelled. The newborn’s initial schemas will most likely center around these external environmental stimuli and the internal sensations associated with basic survival drives such as eating and terminating discomfort. Eventually, some objects will be incorporated within a schema (e.g., objects that do not move), others might require modification of a schema (e.g., objects that can be moved and placed in the newborn’s tiny fingers), while others may require creation of an additional schema (e.g., round objects that move if simply touched). Gradually, concepts will be acquired (e.g., flat objects, round objects, heavy objects, light objects, soft moving objects that make noise and provide food, moving objects that make noise and bathe the infant, other similar looking moving objects that are usually present, other similar looking moving objects that are sometimes present, different looking moving objects that make different sounds and are usually present, etc.).

As the infant’s senses and motor abilities improve and it starts manipulating the environment, it gradually acquires the ability to predict and control what happens. Piaget describes a three-stage sequence of circular reactions (i.e., repetitious behavior) taking place during this first, sensorimotor period of development. Primary circular reactions appear to be repetition of a behavior for its own sake, or perhaps the resultant sensations. Secondary circular reactions consist of the types of behavior demonstrated by Rovee-Colier where the infant repeats an act resulting in a specific environmental effect. Tertiary circular reactions appear to involve attempts by the infant to produce the same environmental effect with different responses. Such attempts typically start to appear at about eight months of age and constitute the first examples of “experimentation.”

In addition to learning that she/he exists as an independent object, Piaget felt that an important concept acquired in the sensorimotor period is object permanence. Initially, children act as though once objects disappear from view they no longer exist; that is, “out of sight, out of mind.” Evidence suggests that children as young as 3-1/2 months old behave as though they understand object permanence. This is inferred from the fact that they look longer at events which turn out different than they apparently anticipated (Baillargeon & DeVos, 1991). For example, it has been shown that young infants will gaze longer at an impossible event (e.g., a toy train appearing to move through a block rather than hitting it (see below) than at a possible event.

Piaget suggested that, at about seven years of age, children advance from the pre-operational stage to the stage of concrete operations. It is at this time that the child appears to understand how certain operations can transform the appearance of objects but not their fundamental characteristics. As shown in the previous video, Piaget developed ingenious tasks for assessing this ability through the demonstration of conservation of number, mass, and liquid volume. Here is another video showing developmental changes in children’s understanding of conservation of number, length and volume.

If you first show a pre-operational child the two rows of five coins lined up so they match (a) and then spread out one of the rows (b) while they are watching , the longer row will be described as having more. They do not yet understand that the operation of moving the objects does not change the quantity. Similarly, a pre-operational child is likely to say that if one of two same-sized balls of clay is rolled into a sausage, it is now larger; or if one of two same-sized glasses containing the same amount of water is poured into a narrower but taller glass, it now has more. Children responding correctly are considered to have advanced to the stage of concrete operations. They understand how the concept of reversibility applies to the operations performed on the row of coins, clay, and liquid. The coins can be moved back to their original positions, the clay sausage rolled back into a ball, and the water poured back into the original glass.

To demonstrate another difference between a pre-operational child and one in the concrete operations stage, Piaget developed a task to determine the ability to perceive someone else’s perspective, as shown in the video. The child was shown a realistic model of a scene including a mountain, toy animals, and plants. The young pre-operational boy only sees the scene from his own perspective. The older boy in the stage of concrete operations is able to imagine the scene from the adult’s position. Piaget and others describe the young boy’s behavior as reflecting egocentrism.

Piaget’s stages describe a progression in the child’s ability to use and manipulate symbols (i.e., to “think”). During the pre-operational stage the child is able to use words to symbolically represent objects and events. During the sensorimotor stage the child is restricted to symbols representing the structuralist’s three basic elements of consciousness; sensations, images, and emotions.

You might be wondering what it means to symbolically represent objects and events in the absence of language. In classic research, Walter Hunter (2013), a student of Harvey Carr’s (one of the early functionalists), tested to see whether his daughter and different animals could symbolically represent the location of an object. The procedure involved a small maze where a light could go on behind one of three “doorways.” If the subject went through the lit doorway, there was food present. There was no food behind the other doorways. This is a simple task for most animals to learn. However, if the light was turned on and then off, a rat could only go to the correct doorway if it oriented itself while the light was still on. Then, it would literally “follow its nose.” If the rat was spun around and released after the light went off, it performed at chance. Raccoons, chimpanzees, and Hunter’s daughter, went to the correct location even though there was no longer an external cue (i.e., light) to guide them. Hunter inferred from this behavior, that these subjects must have symbolically stored information concerning the prior location of the light in order to go to the correct doorway. This ability would have important survival value. For example, if an animal that is not hungry noticed food in a particular location, it would increase the likelihood of survival if it could return to that location when hungry. In addition, this test permitted Hunter to know when he needed to keep his eye on the family cookie jar!

During the concrete operations stage, the child is not only able to symbolically represent objects and events, but is also able to imagine manipulating concrete (i.e., observable) objects and events. The child can imagine moving the coins, squeezing the clay, pouring liquid from one container into another, or moving around the scene of the mountain. Piaget believed his final stage, formal operations, was reached between 12 and 15 years of age (Piaget, 1972; Piaget & Inhelder, 1958). The more adult-like teenager is able to imagine manipulating abstract concepts. For example, without looking at actual objects, an adolescent could be asked “If A is larger than B and B is larger than C, must A be larger than C?” She/he can imagine multiple examples fulfilling the requirements of the statements and arrive at the correct answer. The ability to mentally manipulate abstractions underlies logical thinking, scientific hypothesis testing, and every day problem-solving. The teenager can now execute all the stages of the problem-solving process symbolically: consider how things are, consider how she/he would like them to be, list optional solutions, evaluate the short- and long-term consequences of the different strategies, and arrive at a potential solution.

Piaget’s theory of cognitive development has been extremely influential and generated an enormous amount of empirical research. Piaget, himself, was a gifted child with an early interest in biology. He published several articles by the age of 15! A little known fact is that soon after receiving his doctorate, Piaget moved to Paris and worked with Alfred Binet in constructing items for his seminal school readiness test. Piaget’s stage theory was influenced by the distinct types of errors children of different ages made to certain questions on this test. From these errors, Piaget inferred qualitatively different cognitive styles (pre-operational, concrete operations, and formal operations). Based on his early interests and later work, it is not surprising that the tasks Piaget developed to study cognitive development are oriented toward scientific thinking or that performance on these tasks correlates with school readiness and intelligence tests (Humphreys & Parsons, 1979).

Piaget has been criticized for basing his theory on the observation of a very small non-representative sample of individuals; his three precocious children and the children of highly-educated professionals. Research conducted with more representative samples has generally supported the sequence Piaget described in the ability to solve different types of problems. However, there is considerable variability in the ages at which different children demonstrate the characteristic behavior patterns of the different stages. For example, as previously cited, pre-verbal (i.e., sensorimotor stage) children can demonstrate object permanence (Baillargeon & DeVos, 1991). At the other end of Piaget’s developmental sequence, adults frequently lack or are inconsistent in their usage of formal operational thinking. Piaget (1972) himself recognized this inconsistency. He suggested that experiential differences with different domains of skills (e.g., physics, mathematics, philosophy, etc.) could result in concrete operational type performance in some situations and formal operational performance in others. In the next chapter, we will see that this same pattern of inconsistent performance across situations applies to other human personality characteristics in addition to cognitive style. Some have argued that Piaget fails to appreciate the underlying role of basic cognitive processes (e.g., short-term memory, processing speed, etc.) in movement from stage to stage as well as individual differences (Demetriou & Raftopoulos, 1999; Demetriou, Mouyi, & Spanoudis, 2010). It has been demonstrated that science training improves performance on the Piagetian tasks (Lawson, 1985). Such training effects suggest that movement through the stages is more reliant upon experience than Piaget implies.

Moral Development

Children are completely egoistic; they feel their needs intensely and strive ruthlessly to satisfy them.

It is impossible to overlook the extent to which civilization is built upon a renunciation of instinct.

The first requisite of civilization is that of justice.

Sigmund Freud

Piaget’s interests extended beyond the development of knowledge and skills related to nature (i.e., scientific thinking). He was also deeply interested in the individual’s development of a moral code (Piaget, 1932). Not surprisingly, Piaget believed that the cognitive changes occurring as the child and teenager advanced through the developmental stages influenced their moral thinking as well as their understanding of nature. During the pre-verbal sensorimotor stage, direct learning principles account for changes in behavior. The child increases the frequency of behaviors resulting in appetitive (i.e., “feel good”) or reducing aversive (i.e., “feel bad”) outcomes and suppresses behaviors resulting in aversive or the loss of appetitive outcomes. As the child initially acquires language during the preoperational stage, rules are imposed by adults (primarily parents and caregivers) and understood in a literal, inflexible way. Later, the child gradually interacts with other children, makes friends, and goes to school. The parents’ influence is diluted by the direct and indirect (i.e., observational and verbal) contingencies experienced with different adults (e.g., teachers, members of the clergy, etc.) and their peers. As the child becomes less egocentric during the stage of concrete operations, he/she is able to appreciate the perspectives of others and recognize the possibility and need to cooperate by negotiating rules of conduct. Once attaining the stage of formal operations, teenagers and adults are able to appreciate and consider more subtle and abstract aspects of interpersonal and moral issues (e.g., the benefits and need for fairness, justice, responsibility, etc.).

Kohlberg’s Stage Model of Moral Development

Lawrence Kohlberg (1976) developed a very influential stage model of moral development based on Piaget’s stage model of cognitive development (see Figure 8.11). He distinguished between three different levels (“styles”) of reasoning: pre-conventional, conventional, and post-conventional, each sub-divided for a total of six stages. Pre-conventional morality is based upon extrinsic rewards and punishers. At first, during Piaget’s sensorimotor period, the child is only sensitive to extrinsic rewards and punishers. Once the child acquires speech during Piaget’s pre-operational stage, distinctions between right and wrong are taught by parents and other authority figures. The child learns the value of cooperation (e.g., “I’ll scratch your back and you scratch mine”) once making friends and interacting with others. Conventional morality is based on reference to an authority figure (e.g., parent, teacher, clergy member, etc.) at first and then advances to written sources (e.g., the Bible, Koran, Constitution, etc.). The child acquires a more abstract and flexible understanding of morality once progressing to the stages of concrete and formal operations, . The highest (and rarest) Post-conventional morality level is based on the application of universal principles such as the Golden Rule (Do unto others as you would have others do unto you).

File:Kohlberg Model of Moral Development.svg

Figure 8.3 Kohlberg’s stage theory of moral development.

In attempting to teach codes of moral conduct, much parenting consists of the intentional or non-intentional administration of appetitive and aversive events. We may consider how the different parental styles implement learning procedures and how they may relate to Kohlberg’s levels of moral development (see Figure 8.12).

Indifferent Indulgent Authoritarian Authoritative

Unavailable to monitor behavior, administer consequences consistently, or provide explanations Available to administer non-contingent presentation of appetitive events and provide praise Available to administer contingent presentation of mostly aversive events without explanation Available to administer contingent presentation of appetitive and aversive events with explanation
Pre-Conventional morality Sense of entitlement Conventional morality Post-Conventional morality

Figure 8.4 Parental styles and stages of morality (adapted from Levy, 2013).

Indifferent parents (low demandingness, low responsiveness) do not specify codes of conduct or respond to their children’s needs. If other people (siblings, relatives, peers) do not provide rules and/or consequences, the children will most likely base right and wrong on the outcomes of their actions (if it feels good it is right; if it feels bad it is wrong). Indifferent parenting would appear to be most likely to produce pre-conventional reasoning in children. The authoritarian parenting style would appear likely to result in conventional reasoning and the authoritative style in post-conventional reasoning. Ideally, by providing reasons and explanations in age-appropriate language, our children would internalize principles of moral conduct and apply them appropriately throughout their lives.

Indulgent parents (low demandingness, high responsiveness) do not specify codes of conduct but are affectionate and responsive. They provide “unconditional positive regard” (Rogers, 1957), the type of non-contingent appetitive consequence likely to result in “spoiling” and a sense of entitlement. This could create problems for the children in other contexts (e.g., school, playgrounds) when others react differently to their behavior.

Authoritarian parents (high demandingness, low responsiveness) specify strict codes of conduct in a non-responsive manner. If the children ask for reasons, they may reply “because I say so!” In their parents’ absence, the children would seek other sources of authority.

Authoritative parents (high demandingness, high responsiveness) specify strict codes of conduct within a context of warmth and sensitivity to the children’s needs. They are likely to provide reasons for their codes of conduct, listen to their children’s perspective, and in instances, negotiate alternative codes.

It is very difficult to administer punishment immediately and on a consistent basis in the natural, free-living environment. Therefore, it is not likely that punishment will work as intended, to suppress undesired behavior. Often, instead, the child will learn to become deceptive or lie in order to avoid being punished. Indifferent parents are not likely to be present to appropriately administer punishment and will probably be inconsistent. Indulgent parents are less likely to administer punishment than other parents, if at all. Authoritarian parents (“my way or the highway”) might effectively suppress the undesired behavior when they are present. However, the behavior may occur when they are not present or when the child is in different situations. Authoritative parents, taking advantage of their children’s verbal and reasoning skills, probably have the greatest likelihood of attaining the desired result. For example, an older sibling picking on a younger one might be told the following scenario which includes stipulation of rules of conduct:

There is a difference between a jungle and a society. In the jungle, strong animals often attack weaker animals who receive no protection. Human beings have families and societies in which the strong protect the weak and help them grow stronger. You have to decide whether you want to live in our family and be a member of society. If you keep picking on your little brother/sister, we will need to treat you like an animal from the jungle. We put dangerous animals in a zoo so they cannot hurt anyone, so we will keep you in your room. If you take care of your little brother/sister, mommy and daddy will let you play together and have fun.

By relying upon language to stipulate and enforce rules in this manner, a parent is most likely to achieve the short-term objective of encouraging appropriate and discouraging inappropriate behavior. In addition, by providing thoughtful explanations and justifications of rules, the parent increases the likelihood that the child will internalize a moral code of conduct as he/she matures.

Erik Erikson’s Stage Theory of Lifespan Development

Erik Erikson (1950; 1959) proposed a “cradle to grave” sequence of development which complements the stage theories of Piaget and Kohlberg. Erikson described eight “conflicts” associated with different periods of one’s life (see video). It was assumed that successful resolution of the conflict associated with a particular stage resulted in acquisition of the related “virtue” (e.g., trust, autonomy, initiative, etc.) for the rest of one’s life. Unsuccessful resolution would result in developmental problems during subsequent stages.


During Erikson’s first (infancy) stage, taking place during Piaget’s pre-verbal sensorimotor stage, the attachment style of the caregiver will influence whether or not the infant experiences a nurturing and responsive social environment. If the caregiver is consistent in satisfying the basic needs for food, comfort, and relief from pain, the infant learns to trust them. If negligent, inconsistent, or abusive, the child will mistrust and perhaps fear the caregiver.

In the second (early childhood) stage, starting toward the end of Piaget’s sensorimotor stage and extending into the beginning of the verbal preoperational stage, the young child is exploring and learning to control the environment on its own. A patient caregiver waits until the zone of proximal development is reached and applies encouraging, supportive scaffolding techniques during toilet training and other learning experiences. Such a parent is likely to insure the child’s success, resulting in the feeling of independence and autonomy. If the child is hurried, scolded, or punished for failures, she/he may feel shame and doubt her/his capabilities.

In the third (preschool) stage, occurring in the middle of Piaget’s preoperational stage, the child must learn to dress and groom in a manner consistent with social norms and standards. If the child is encouraged to explore options, satisfy its curiosity, and express its own preferences and interests, it is likely to develop initiative. If discouraged, the child may become passive and doubtful of its own capabilities and experience guilt regarding its choices.

Erikson’s lengthy fourth (school age) stage starts toward the end of Piaget’s preoperational stage and extends through concrete operations into the beginning of the final formal operations stage. If at home and school, the child is appropriately challenged and succeeds at progressively more difficult tasks, it becomes competent, confident, and industrious. The child must experience and learn to cope with frustration and inevitable failure. It is during this stage that the child becomes concerned about its own performance in comparison to others in and out of school. Feelings of inferiority can result from perceived inadequacies and negative social comparisons.

Adolescence and Adulthood

Adolescence: Preparing for Adulthood

Anatomy is destiny.

Love and work… work and love, that’s all there is.

Sigmund Freud

“Sex, drugs, and rock & roll”

Life Magazine, 1969

Congratulations, your child has made it to Piaget’s formal operations and Kohlberg’s conventional moral stages and is a trusting, independent, guilt-free, industrious teenager. Erikson’s fifth (adolescence) stage takes place during the middle-school and high-school years. This period can include substantial peer-pressure as students compare their physical appearance, school performance, personal characteristics, and personal possessions with others. Erikson is perhaps most famous for coining the term “identity crisis” to refer to the characteristic questioning of one’s personal qualities, goals, and social roles during his fifth developmental stage. Parental tensions between the desire to protect one’s child and the need to foster independence can result in an increase in the frequency and intensity of conflicts and arguments during this stage. It is tempting to volunteer suggestions or to impose solutions on a teenager struggling with identity issues. Peers are replacing parents as the primary role models and sources of reinforcement. Personal choices can have significant impacts upon the course of one’s life and pose significant dangers. It is a period marked by experimentation with hobbies, jobs, grooming habits, dress styles, sexual practices, alcohol, drugs, music and media, religious participation, and political beliefs. Negotiating the fine line between helpful guidance (scaffolding) and interference, is difficult for parents as the teenager struggles to attain a unique identity. Non-requested suggestions or attempts to enforce restrictions can result in identity confusion.

James Marcia (1966) developed a model addressing Erikson’s identity crisis. Marcia distinguished between four different identity states based on two considerations; had exploration occurred and had a commitment been made.

Identity issues could include relationships (friends and/or romantic partners), gender roles, religion, politics, interest in attending higher education, future vocation, etc. As implied by Erikson, it is desirable that the adolescent be exposed to and permitted to explore various options for each of these issues. Only then, could the adolescent make an informed decision regarding whether to commit to a particular choice, thereby attaining identity achievement. If commitment occurs without the ability to explore options (e.g., a parent’s making the decision regarding a romantic partner or future career) identity foreclosure occurs. Moratorium refers to the continual stage of exploring prior to making a commitment. Identity diffusion occurs when one never addresses identity issues or commits to a specific choice.

Freud remains current in his observation that the human condition includes the two major developmental tasks of preparing for love and work. The beginning of adolescence is demarcated by the onset of puberty as males and females gradually become physically capable of reproduction. Associated is the development of a new and powerful basic drive. The Nukak have no reason to discourage sexuality or delay child-bearing. As soon as males and females are ready, they pair off and usually form monogamous relationships. Living in the low-density population rainforest means that there are very few available potential mates. This has its advantages (e.g., a relatively simple and low-stress “courtship” period) and disadvantages (extremely limited choice).

We live very different lives than the Nukak as the result of centuries of civilization and available technologies. Industrialization resulted in people moving from predominantly rural, low-density population, agricultural lifestyles to urban, high-density population, manufacturing lifestyles. Many of the jobs created were dangerous and some required advanced intellectual skills. This raised the need and desire for compulsory education toward the end of the 19th century. In 1890, 5% of American 14-17 year-olds were enrolled in high school. By 1970, 90% were enrolled (Tanner, 1972). The requirement to attend school meant delaying becoming independent from one’s parents and starting a family. G. Stanley Hall suggested the need for a new developmental stage to refer to this delay period between childhood and adulthood. He called it adolescence (Hall, 1904), derived from the Latin word adolescentem meaning to mature, or grow up.


Congratulations! Thanks to the magic of fast-forward developmental psychology, your pretend child has caught up with you and is a college student. What do you want to be when you grow up? Interestingly, your pretend child catching up with you puts you in a similar situation to your parents. You might be considering what you would like your child to become. Your answers for both yourself and your pretend child probably continue to relate to Freuds’s two major developmental tasks: finding a partner in life; attaining suitable, stimulating, and enjoyable work. Unlike the Nukak, you and your young adult theoretically have an enormous choice of potential life partners and occupations. This is true, even in comparison to relatively recent generations of city dwellers. The internet has introduced globalization to pairing off as well as to the marketplace. We live in a hyper-connected world where geographic distance no longer necessarily limits our opportunities to meet or communicate with others.

The same trend observed with high school attendance also applies to college attendance. In 1890, less than 5% of 18-21 year-olds were enrolled in college. By 1990 this number exceeded 60% (Arnett & Taber, 1994). No doubt this percentage will continue to increase in the future and we will observe similar trends in graduate and post-graduate education. Thanks to machinery reducing the need for physical strength and the availability of contraception, anatomy is not necessarily the dominating force in a woman’s destiny that it was in the past. Opportunities for women enormously expanded during the past two generations as we transitioned to an economy based upon service and information. In 1950, the average age of marriage was 23 for men and 20 for women in the United States. By 2000 these ages had increased to 27 and 25, respectively (Arnett, 2000). Due to the educational requirements of many current vocations in technologically-advanced societies, there is usually the need to delay financial independence from one’s parents and starting a family even longer than when Hall proposed the adolescent developmental stage. Arnett (2000) suggested the need to add emerging adulthood as another developmental phase between the end of adolescence (e.g., graduation from high school at about the age of 18) and adulthood (financial independence, living apart from one’s parents, starting a family, etc.). Arnett found that many college students report feeling “in between” adolescence and adulthood, consistent with considering emerging adulthood an intermediary stage of development. If you were to define yourself as being in a developmental stage, would you consider yourself an adolescent, adult, or emerging adult? What would you consider your pretend student at the start of the freshman year?

Erikson’s sixth through eighth stages consist of young adulthood, middle adulthood, and maturity (see Figure 8.14). In the rainforest, the major developmental transition occurs when children leave their parents’ home to mate and have children. Life in the developed world is marked by minor transitions from elementary- to middle-school and middle-school to high school. Those who fail to graduate high school tend to fare poorly in the increasingly skills- and education-oriented global economy. Even high school graduates can have difficulty finding jobs when there are downturns in the economy. Taking on the responsibilities of adulthood at about 18 years of age necessarily limits ones career (and associated economic) options. The extent of your education will also probably affect whom you find suitable as a mate and vice-versa. If you are attending college, it is likely that your parents considered these economic and social realities in supporting this goal.

As indicated previously, a substantial majority of contemporary high school students go on to college. This almost always results in delaying the start of a career or a family. These students would be considered by Arnett (2000) to be in the emerging adult stage until taking on the responsibilities associated with being an adult. The identity issues characteristic of Erikson’s adolescent stage carry over into emerging adulthood for those attending college and graduate school. Marcia’s (1966) emphasis on the importance of exploring options and making commitments remains appropriate. In addition to being a time to study and advance in your pursuit of a career, it is a time for meeting new potential friends and romantic partners. The commitments you make to a career and romantic partner will have major impacts upon the success and enjoyment you experience during middle adulthood and the likelihood of having disappointments and regrets when you reflect back on your life.

Putting It All Together: Looking Back

As an exercise for ending the human development chapter, I would like you to consider how the material helps you understand the factors which made you the unique person you are. Think of the importance each of the following played at different points of your life:

  • Heredity
  • Health (including nutrition, alcohol, and drugs)
  • Parents and caregivers
  • Siblings
  • Other family members
  • Friends from the sandbox through high school
  • Where you grew up, including community activities and problems
  • Schools
  • Religion
  • Jobs
  • Sports
  • Hobbies
  • Music and the Arts
  • Technology (including cars, computers, cell phones, the internet, etc.)

It might prove meaningful to consider the role each of these played during the ages corresponding to Piaget’s, Kohlberg’s and Erikson’s stages. Previously, I indicated the inappropriateness of considering stage theories as explanations. Information concerning specific genes and experiences is not provided. Stage theories can, however, provide valuable perspectives for describing and understanding the important behavioral changes that appear characteristic of the human condition. This is true whether describing a child growing up in the rain forest or a modern city.

Putting It All Together: Looking Forward

You may also wish to consider how the information in this chapter helps you plan for your future, including the possibility of becoming a parent. Are there implications regarding who you would like to become in the future and for accomplishing your goals? What are the implications of the findings regarding different parenting styles should you decide to trade in your pretend child for the real thing? Major issues you may wish to consider include how to address gender roles, which toys and technologies to introduce, and when and how to introduce them.

File:First Shave.jpg

File:Happy child 2.jpg

Figures 8.4 and 8.5 Male and female gender roles.

We can consider the implications of transformation of the human condition to the development of human potential. Whether growing up in the rainforest or city, much of a child’s capabilities are increased by genetically influenced growth and neurological changes. Improved observational learning skills and the introduction of speech enables the application of more effective and efficient indirect learning principles. All healthy children possess the potential to adapt to their environment. The pictures of members of the Nukak tribe remind us of the extreme differences in the human condition that currently exist on our planet. The manufactured picture of the changes occurring on Manhattan Island over the past 400 years, dramatically reveals how technology has transformed the natural human condition (i.e., the planet earth) to one created by humans themselves. This may seem like science fiction, but we appear on the verge of creating a third, virtual, human condition. One of the most popular choices for a self-control project in my classes the past few years, has addressed some form of computer or cell phone usage. Contemporary college students are spending substantial parts of their life (i.e., large slices of their personal pie charts) on social networking sites, playing video games, texting, and so on. The virtual community Second Life is popular. For many, it and other internet sites are becoming the person’s first life!

Your generation’s children will be exposed to natural, human-manufactured, and virtual realities from birth (or earlier?). Parents and other caregivers, as always, will need to keep Vygotsky’s principles of the zone of proximal development and scaffolding in mind as they help children adapt to their ever-increasing choices regarding the human condition.