Chapter 9: Personality and Human Potential

Learning Objectives

  • Describe the Big Five personality dimensions
  • Give examples of direct and indirect genetic influences on personality
  • Describe how adaptive learning relates to socialization, culture, and personality development

Trait Theories of Personality

’cause you got personality,
Walk, personality
Talk, Personality
Smile, Personality
Charm, personality
Love, personality
And of Cause you’ve got
A great big heart

From the song Personality by Lloyd Price

As the Lloyd Price song describes, do you think you “got” (i.e., have (a) personality)? How would you describe your personality? As a follow-up to the developmental psychology chapter and introduction to the chapter on personality, it might be fun to engage in a bit of romantic fantasy and develop your priorities for a partner in life. Try to construct an ordered list of those personality qualities you consider most important for your partner. Research with college students surveying the desirable qualities college students sought in a potential mate resulted in the following list: ‘‘kind and understanding,” ‘‘religious,” ‘‘exciting personality,” ‘‘creative and artistic,” ‘‘good housekeeper,” ‘‘intelligent,” ‘‘good earning capacity” (i.e., provider), ‘‘wants children,” ‘‘easygoing,” ‘‘good heredity,” ‘‘college graduate,” ‘‘physically attractive,” and ‘‘healthy” (Buss & Barnes, 1986).

Would you list similar qualities to those of the college students in the research study? Many of those qualities can be considered traits; an individual’s patterns of behavior (including thoughts and feelings) that are consistent across time and situations. Traits often refer to extreme points on a continuum; for example, kind vs. unkind (mean), intelligent vs. unintelligent (slow), easygoing vs. serious, exciting vs. unexciting (dull), creative vs. uncreative (rigid), and religious vs. irreligious in the list above. Other terms in the research study refer to extreme points on a continuum of physical characteristics (e.g., attractive vs. unattractive, healthy vs. unhealthy, good heredity vs. poor heredity) or to specific behavioral outcomes (e.g., college graduate vs. not, good provider vs. not, wants kids vs. not, good housekeeper vs. not). How many of these qualities would you include on your list? Do you agree with including each of them? What important qualities do you think were left out? Would you consider these qualities to be a description of his/her personality? Do you think your parents would have the same priorities as you?

In a study, college students and their parents were asked to rank these 13 different traits for desirability in a potential long-term life partner for themselves or their children (Perilloux, Fleischman, & Buss, 2011). The traits were scored such that the value (between 1 and 13) indicated importance of the trait. The average rankings for sons, daughters, fathers, and mothers are listed in Figure 9.1. Before you look at the findings, you might find it interesting and informative to rank order these 13 traits based on your own priorities. Assign the score of 13 to your highest priority characteristic and 1 to your least important. By ranking the items yourself, you can see how your priorities compare to the college students of your own sex, the opposite sex, and fathers and mothers in the study.

Sons (Mean) Daughters (Mean) Fathers (Mean) Mothers (Mean)

Attractive (10.70) Kind (11.57) Kind (11.50) Kind (11.62)

Intelligent (10.40) Intelligent (10.40) Intelligent (10.56) Intelligent (10.36)

Kind (10.00) Personality (8.97) Healthy (9.22) Healthy (9.00)

Personality (8.88) Attractive (8.08) Provider (7.43) Easygoing (7.79)

Healthy (8.79) Healthy (7.97) Easygoing (7.29) College graduate (7.29)

Easygoing (8.63) Easygoing (7.59) College graduate (6.85) Provider (7.28)

Creative (5.66) Provider (7.42) Personality (6.75) Religious (6.64)

Wants kids (5.94) College graduate (6.99) Religious (6.52) Wants kids (6.40)

College graduate (5.46) Wants kids (6.09) Attractive (5.91) Personality (6.07)

Heredity (5.16) Creative (4.64) Heredity (5.31) Attractive (5.66)

Provider (4.25) Heredity (4.58) Wants kids (5.09) Heredity (5.24)

Housekeeper (3.98) Religious (3.93) Creative (4.99) Creative (4.37)

Religious (3.48) Housekeeper (2.81) Housekeeper (3.58) Housekeeper (3.27)

Figure 9.1. Overall rankings of desirable traits for a mate by male and female college students and their parents (adapted from Perilloux, Fleischman, & Buss, 2011).

The items are listed with the highest priority (i.e., score closest to 13) at the top and lowest priority (i.e., score closest to 1) at the bottom. If you are a woman, did you rate kindness as most important, followed by intelligence, an “exciting” personality, attractiveness, health, and being easygoing? If you are a man, did you consider attractiveness most important, followed by intelligence, kindness, “exciting” personality, health, and being easygoing? Are you surprised or not by the fact that male and female college students included the same six items as most important? Are you surprised by the differences in their rankings of these six qualities? It is also informative to compare the means as well as the rankings. For example, even though an exciting personality is rated third by women and fourth by men, the means are almost the same. If you are seeing someone, would you be interested in how they rank the different traits? It might be fun, not to mention informative, to compare and discuss the results. If you are not seeing someone, would you be interested in the priorities of a potential date? How about sitting them down and giving them the list as an “ice breaker?” At least you can find out if they are easygoing! Good luck!

Are you at all surprised by the differences between parents and their children? Religiousness, health, earning capacity, and housekeeping seem a lot more important to parents than to college students. In contrast, attractiveness and an exciting personality were more important to the students. How do you think your parents would rank the traits if they were considering your potential partner in life? Let’s make you a pretend parent again. If you were ranking the items for your pretend child, would you score them the same as you did for yourself or would your rankings be similar to the parents in the study? Would things change if your pretend child was the other sex? Can you relate to where your parents may be coming from? Do you have a little brother and/or sister? How would you rank the different traits if you were choosing a life partner for them? Would the rankings be more similar to the ones you use for your children or for yourself? Do you remember the marshmallow test from Chapter 1? Choosing a partner in life may be the most important “marshmallow test” you ever take. I mentioned that you are more likely to purchase healthful foods if you shop from a list. Make sure you have the right list with you when you go shopping for a partner in life! I hope this exercise helps.

Personality as Temperaments

Speculation regarding the structure and causes of human personality date back to the time of Hippocrates (460-370 BC). The Greek physician, best known for medicine’s Hippocratic Oath, proposed that our moods and behavior were influenced by the relative amounts of four body liquids (“humors”): blood, black bile, yellow bile, and phlegm. Later, Galen (AD 131–200) expanded upon Hippocrates, suggesting excessive quantities of any of these liquids would lead to a specific, inherited temperament: “sanguine” (outgoing, impulsive, and creative) for blood, “melancholic” (shy, cautious, and moody) for black bile, “choleric” (aggressive, goal-directed, and ambitious) for yellow bile, and “phlegmatic” (kind, relaxed, and reliable) for phlegm (Kagan, 1998).

Figure 9.2 The Four Temperaments by Charles La Brun.

The idea expressed by Hippocrates and Galen, that human personality can be categorized into distinct types, survived through the centuries and served as the basis for trait theory. This 2500 year history is an enormously long-lasting example of “the more things change, the more they stay the same.” Hippocrates and Galen proposed four basic temperaments. As you will see, decades of research on traits has sometimes seen this number substantially expanded, sometimes shrunk, and more recently, increased by one to five (see below). Eventually, theorists returned to considering innate differences in temperaments. We’ve come a long way in two-and-a-half millennia but do not appear to have moved too far!

Hippocrates and Galen thought that four different human temperaments (i.e., personalities) resulted from the relative concentrations of blood, black bile, yellow bile, and phlegm in the body. Today, this might strike you as absurd, and indeed, we now know that it is incorrect. Hippocrates and Galen’s belief might be considered a theory of personality. A theory is a scientific schema used to provide a cohesive network of relationships between independent and dependent variables. As such, theories attempt to explain as much of nature as possible (be it physical, chemical, biological, or psychological) with as few assumptions as possible. Hippocrates and Galen proposed a very simple theory of personality based on the four humors. The most important characteristic of a theory is that it is testable. It must make specific predictions concerning the relationships between independent and dependent variables. In that regard, Hippocrates and Galen proposed a useful theory since it was testable. We now have the necessary tools and technologies to measure the precise quantities of the four humors and whether they relate to the tendencies to behave in outgoing or shy, aggressive or passive, or other ways. In terms of theory construction, it is better to be wrong than vague. Knowledge and understanding are advanced when we know that something is not true. Knowledge and understanding are not advanced when a theory is so vaguely stated that it can account for any result. We will describe three different theoretical approaches to the understanding of human personality: Trait theory, Freud’s psychodynamic theory, and learning theory.

Personality as Traits

The psychological study of personality can be said to have originated with Gordon Allport’s dictionary search resulting in a listing of 4500 trait-related words (Allport & Odbert, 1936) and his publication of Personality: A psychological interpretation (Allport 1937). Raymond Cattell (1943; 1946) shrunk Allport’s list to 171 by combining synonyms (e.g., extroverted, outgoing, boisterous, etc.) and eliminating extremely rare examples (e.g., obscurant and obsequious among the “obs”s, etc.). He then scored a large sample of adults on these 171 items. Cattell used the statistical technique, factor analysis, to determine the extent to which the effects of the different items overlapped. Based on the results, Cattell was able to reduce the number of primary human personality factors to sixteen. Figure 9.3 lists the 16 primary factors along with descriptions of the types of behaviors characteristic of low and high scorers.

Descriptors of Low Range Primary Factor Descriptors of High Range
Impersonal, distant, cool, reserved, detached, formal, aloof Warmth
Warm, outgoing, attentive to others, kindly, easy-going, participating, likes people
Concrete thinking, lower general mental capacity, less intelligent, unable to handle abstract problems Reasoning
Abstract-thinking, more intelligent, bright, higher general mental capacity, fast learner
Reactive emotionally, changeable, affected by feelings, emotionally less stable, easily upset Emotional Stability
Emotionally stable, adaptive, mature, faces reality calmly
Deferential, cooperative, avoids conflict, submissive, humble, obedient, easily led, docile, accommodating Dominance
Dominant, forceful, assertive, aggressive, competitive, stubborn, bossy
Serious, restrained, prudent, taciturn, introspective, silent Liveliness
Lively, animated, spontaneous, enthusiastic, happy go lucky, cheerful, expressive, impulsive
Expedient, nonconforming, disregards rules, self-indulgent Rule-Consciousness
Rule-conscious, dutiful, conscientious, conforming, moralistic, staid, rule bound
Shy, threat-sensitive, timid, hesitant, intimidated Social Boldness
Socially bold, venturesome, thick skinned, uninhibited
Utilitarian, objective, unsentimental, tough minded, self-reliant, no-nonsense, rough Sensitivity
Sensitive, aesthetic, sentimental, tender minded, intuitive, refined
Trusting, unsuspecting, accepting, unconditional, easy Vigilance
Vigilant, suspicious, skeptical, distrustful, oppositional
Grounded, practical, prosaic, solution oriented, steady, conventional Abstractedness
Abstract, imaginative, absent minded, impractical, absorbed in ideas
Forthright, genuine, artless, open, guileless, naive, unpretentious, involved Privateness
Private, discreet, nondisclosing, shrewd, polished, worldly, astute, diplomatic
Self-Assured, unworried, complacent, secure, free of guilt, confident, self-satisfied Apprehension
Apprehensive, self-doubting, worried, guilt prone, insecure, worrying, self- blaming
Traditional, attached to familiar, conservative, respecting traditional ideas Openness to Change
Open to change, experimental, liberal, analytical, critical, free thinking, flexibility
Group-oriented, affiliative, a joiner and follower dependent Self-Reliance
Self-reliant, solitary, resourceful, individualistic, self-sufficient
Tolerates disorder, unexacting, flexible, undisciplined, lax, self-conflict, impulsive, careless of social rules, uncontrolled Perfectionism
Perfectionistic, organized, compulsive, self-disciplined, socially precise, exacting will power, control, self-sentimental
Relaxed, placid, tranquil, torpid, patient, composed low drive Tension
Tense, high energy, impatient, driven, frustrated, over wrought, time driven.

Figure 9.3 Cattell’s 16 primary personality factors.

Cattell went one step further, conducting a factor analysis on these 16 primary traits, and identified “the Big Five” global, secondary trait dimensions: introversion/extraversion; low anxiety/high anxiety; receptivity (i.e., open-mindedness/tough- (i.e., closed-) mindedness); accommodation (i.e., dependence)/ independence; and lack of restraint (i.e., impulsive)/self-control. Figure 9.4 shows how the “Big Five” relate to the 16 primary factors.

Introversion / Extraversion Low Anxiety / High Anxiety Receptivity / Tough-Mindedness Accommodation / Independence Lack of Restraint / Self-Control
A: Reserved / Warm C: Emotionally Stable / Reactive A: Warm / Reserved E: Deferential / Dominant F: Serious / Lively B: Problem-Solving
F: Serious / Lively L: Trusting / Vigilant I: Sensitive / Unsentimental H: Shy / Bold G: Expedient / Rule-Conscious
H: Shy / Bold O: Self-Assured / Apprehensive M: Abstracted / Practical L: Trusting / Vigilant M: Abstracted / Practical
N: Private / Forthright Q4: Relaxed / Tense Q1: Open-to-Change / Traditional Q1: Traditional / Open-to-Change Q3: Tolerates Disorder / Perfectionistic
Q2: Self-Reliant / Group-Oriented

Figure 9.4 Relationship between Cattell’s “Big Five” secondary global traits and the 16 primary factors.

In 1949, Cattell published the very popular 16 Personality Factor Questionnaire (16PF), currently in its fifth edition (Cattell, R. B., Cattell, A. K., & Cattell, H. E. P., 1993). The latest edition includes 185 multiple-choice items designed to assess the 16 primary and five global traits. The items ask about the occurrence of concrete, everyday behaviors, rather than asking the person to simply rate themselves on the traits. Examples include such items as:

  • When I find myself in a boring situation, I usually “tune out” and daydream about other things. True/False.
  • When a bit of tact and convincing is needed to get people moving, I’m usually the one who does it. True/False.

The Big Five

Figure 9.5 lists the characteristics of low and high scorers on the Big Five personality dimensions. How do you think you would score on these five dimensions?

big five personality traits peats

Figure 9.5 The Big Five personality dimensions.

The British psychologist, Hans Eyesenck, felt that the combination of introversion/extraversion and neuroticism/emotional stability was adequate to capture the personality of normal (i.e., non-psychotic) individuals. Do you agree? Do you think the “Big Five” factors are adequate to describe your personality or do you need all 16 items? Which do you prefer, the items listed in the Perilloux et al. (2011) study, the 16 primary traits, the Big Five, or Eysenck’s two dimensions, as a tool for assessing and describing your personality? Returning to thinking about the qualities you would like your life partner to possess; which of these approaches would you use? How would you like him/her to score on each of the items?

Contemporary personality theorists have concluded that Eysenck’s two (or three) dimensions are inadequate and Cattell’s 16 factors unnecessarily overlapping. The Big Five has consensually emerged as being adequate to describe the basic components of human personality (Cattell, 1996; Digman, 1989; Goldberg, 1981; McCrae & Costa, 1987; McCrae & John, 1992). McCrae and his colleagues translated a Big Five self-report inventory into 29 languages and administered it to almost 18,000 individuals belonging to 56 nations. The data supports the applicability of the Big Five personality dimensions across these diverse cultures (Costa, Terracciano, & McCrae, 2001; McCrae, 2002; McCrae & Allik, 2002; McCrae, Terracciano, et al, 2005). Interestingly, consistent sex differences have been found across 55 cultures (Schmitt, 2005; Schmitt, Realo, Voracek, & Allik, J., 2008). In most countries, women were found to score higher than men in neuroticism, extraversion, agreeableness, and conscientiousness. Differences in the sexes were greater in technologically-enhanced, egalitarian cultures than more primitive, paternalistic cultures. It is under more egalitarian educational and economic conditions that biology does not constitute destiny for women and they are better able to fulfill their potential by expressing their individuality.

Personality and Nature/Nurture

Freud’s Psychodynamic Theory of Personality: Nurture against Nature

Image result for sigmund freud

Figure 9.6 Sigmund Freud

Arguably, one of the most influential and controversial figures in the history of Psychology is the Viennese physician, Sigmund Freud (Figure 9.6). Certain facts must be kept in mind when evaluating Freud’s contributions to psychology. First, Freud’s model of personality predates Allport’s introduction of trait theory. Second, Freud did not contribute to or interact with the early schools of psychology; structuralism, functionalism, Gestalt psychology, and behaviorism. Second, he was a practitioner, not a scientist. He was a physician, who would today be considered a psychiatrist, treating individuals suffering from psychological and/or psychiatric complaints. An astute observer of human behavior, he proposed general models of human personality and abnormal psychology based on the case history material obtained from a small sample of non-representative individuals. Based on his clinical observations, Freud concluded that humans are unaware of most of the factors that influence their thoughts, feelings, and behavior. This perceptive and important assumption is often portrayed as an iceberg (see Figure 9.7).

Figure 9.7 Freud’s theory of personality.

Freud distinguished between those things of which we are currently aware (i.e., the contents of short-term memory); those things which we can voluntarily retrieve (i.e., the contents of long-term memory); and those things we ordinarily cannot voluntarily retrieve. Freud felt thoughts related to our essential sexual and aggressive natures created conflict and must ordinarily be prevented from reaching consciousness. He postulated the existence of different defense mechanisms to accomplish this objective. The assumption of unconscious psychic determinism is perhaps Freud’s greatest lasting contribution. The assumption argues for the appropriate use of the scientific method to study psychology. There are presumed causes which may be difficult to study, since they are “below the surface” of consciousness. However, with the same ingenuity demonstrated by other natural sciences, there is the potential to explain the totality of human experience. As we will see in Chapter 11, Freud’s approach to the assessment and treatment of human disorders is essentially the attempt to bring unconscious material to consciousness.

Perhaps best known, is the three-part psychic apparatus Freud (1920; 1923) created to “explain” human personality and behavior. He described the human condition as a “tug of war” between one’s genetically determined and entirely unconscious drives (called the Id) and one’s mostly unconscious conscience (the superego). The mostly conscious ego was the component of the psychic apparatus that must reconcile these opposing objectives and the demands of reality. According to Freud, “The poor ego has a still harder time of it; it has to serve three harsh masters, and it has to do its best to reconcile the claims and demands of all three… The three tyrants are the external world, the superego, and the id (Freud, 1933, lecture 31).”

Although Freud never attempted to do so, it is possible to relate his three-part psychic apparatus to the basic psychological content areas and research findings of psychology. In fairness, we now know a lot more than we did at the time Freud proposed psychodynamic theory. Often, not only was he perceptive, but in many instances he was prescient (e.g., proposing that we are often not aware of factors influencing our behavior; describing self-control problems stemming from the power of short-term as opposed to long-term consequences; making distinctions between short- and long-term memory; emphasizing the important role of observational learning and language in moral development, etc).

The advantage of relating Freudian theory to the basic content areas of psychology is that by doing so, one avoids the common tendencies of reification and pseudo-explantion. Reification refers to describing hypothetical structures as though they were physical structures. Freud intended the id, superego, and ego to represent related processes taking place at different locations in the body. That is, they were intended to be functional units (akin to the digestive system), not anatomical units (e.g., the stomach). It is tempting and convenient to attribute one’s failure to resist temptation to a defective id. How do you know your id is defective? I gave in to temptation. Why did you give in to temptation. My id is defective.

Freud’s id, operating according to the pleasure principle, is a variation on the Greek hedonic model of motivation described in Chapter 4. Postulating a pleasure principle is one thing; providing details regarding how it works is eventually required. Chapter 4 describes findings related to deprivation of appetitive substances, the physiology of the sex drive, the need for sleep, and such human needs as curiosity, achievement, and self-actualization. These findings bring us much closer to understanding the effects of many motivational independent variables (e.g., amount of food deprivation, intensity of shock, etc.) on human thought, emotion, and behavior.

Freud believed the superego was formed through identification with one’s parents. The section of Chapter 6 describing observational learning directly relates to Freud’s process of identification. The two most powerful classes of variables influencing the likelihood of attending to a model are perceived similarity to self and reinforcemnt value. Throughout infancy, practically all of the people one comes into contact with live in one’s home and are probably family members (most often one’s parents and siblings). The infant has limited opportunities to meet children outside the home that may be perceived as being similar. Naturally, the caregivers (usually parents) provide food and comfort, controlling the most powerful reinforcers in the infant’s world. As the child grows up, plays with other children, and goes to school, peers become increasingly influential. The Moral Development section of the previous chapter directly relates to Freud’s superego. We saw how Baumrind’s different parental styles could impact the development of the concepts of right and wrong throughout childhood, perhaps producing the behaviors characterizing Kohlberg’s pre-conventional, conventional, and post-conventional stages.

Whereas Freud described the id as operating according to the hedonic pleasure principle, the ego was described as operating accoring to the reality principle. Much of the material in the Direct Learning (Chapter 5), Indirect Learning (Chapter 6), and Cognition (Chapter 7) chapters relates to ego functioning. The ego’s attempt to satisfy three harsh masters (id, supergo, and reality) may be described as an exercise in problem-solving. One’s experiences interacting with the world, observing others, and acquiring information through the use of language, result in a personal understanding of how the world works (i.e., reality). This understanding may be applied to situations in which one must determine and assess the possible short- and long-term consequences of following different courses of action.

Freudian theory and nature/nurture

Part of the reason for the influence of Freudian theory is his fascinating and exciting description of the human condition as a conscious struggle (conducted by the ego) between our inherited drives and needs (the id) and the moral demands placed on us by civilized society (the superego). Freud was a gifted writer with an authoritative and engaging style. His portrayal of the human condition not only influenced the disciplines of psychiatry and psychology, but immediately captured the imagination of scholars in other disciplines, writers, and the general public. Freud describes the human condition as requiring our conscious (and learned) moral codes and understanding of reality to counteract our unconscious (and unlearned) animalistic and impulsive drives. The idea of primitive urges creating difficulties coping with the modern world is plausible and compelling. It is also consistent with themes of this book regarding our having biologically evolved to survive under naturalistic conditions but currently living in a human constructed world.

Freud’s three-part psychic apparatus adheres to a nurture (learning) against nature (heredity) model of personality. The discipline of psychology assumes a complimentary relationship between nature and nurture. Different research strategies have been developed for disentangling and weighing the influences of nature and nurture in the development of human personality. It has always been possible to systematically study experiential effects on behavior in a correlational manner. For example, one can ask individuals about the parental styles they were exposed to as children and assess the relationships with performance on personality tests, moral dilemmas, interpersonal interactions, etc. Psychology has a rich history of studying experimental manipulations of experience on perception, learning, and cognition, as documented in previous chapters. We live at a time when it is becoming possible to experimentally manipulate specific genes in order to determine their influences on specific behaviors. Previously, it was necessary to resort to much cruder and less powerful correlational methods to try to determine the effects of heredity. Correlational research strategies include cross-cultural research, twin studies, and adoption studies.

Cross-Cultural Research

How can we understand the variations and consistencies in human personality? Cross-cultural research provides a type of “natural experiment” relating to such nature/nurture issues. If one sees similarities across cultures, it is likely that hereditary factors are involved since experiential factors are so varied. Similarly, if one sees substantial cultural differences, it is likely that experiential variables are responsible. The contemporary field of evolutionary psychology assumes that we can understand cultural similarities as resulting from psychological adaptations conferring survival and/or reproductive advantages (Buss, 2011). We have seen previous attempts to understand surprising behavioral findings with other animals by considering possible survival advantages. For example, we attributed the counter-intuitive finding that animals become more, rather than less active when deprived, to the fact that activity increases the likelihood of discovering the needed substance. Some have attempted to extend this same type of reasoning to the understanding of complex human behavior.

As an example, all known human cultures speak. Thus, it appears that genetics plays an important role in speech. In Chapter 1, we saw how specific DNA is dedicated to the formation of words in the mouth, and In Chapter 2, we described how considerable “brain space” is dedicated to the parts of the body associated with speech. Despite the fact that all human cultures speak, they speak different languages. In Chapter 5, we described the role of classical conditioning procedures in establishing word meaning and in Chapter 6, we saw how learning principles apply to the acquisition of speaking, reading, and writing. From the perspective of evolutionary psychology, the ability to speak increases the likelihood of human survival and reproduction. However, the specific words and grammar that an individual acquires reflects the adaptive learning requirements of the immediate social environment.

Evolutionary psychology has attempted to explain the sex differences found in the previously described research assessing the differences between males and females in the qualities they desire in a mate. Buss (1989) reasoned that for thousands of years, men and women faced different adaptive needs. Women bore children and were primarily responsible for nurturing and rearing them. They required the time and resources necessary to achieve these objectives. Men needed to impregnate women in order to enable survival of the species. They were concerned with paternity uncertainty and the possibility of providing time and resources to another man’s children. According to evolutionary psychology, it is these different adaptive needs that resulted in women preferring older men possessing higher social status along with the ability to protect them and provide necessary resources. Men are attracted to young, attractive mates likely to possess the ability to conceive, and strength to survive multiple pregnancies and rear several children. Consistent with these interpretations, research findings indicate different types of jealousy in females and males. Women were found to be more concerned with emotional than sexual infidelity whereas the reverse was true for men (Pietrzak, Laird, Stevens, & Thompson, 2002). A man becoming emotionally attached to another woman could result in loss of social status and resources. A woman’s sexual activity with another man could result in pregnancy and dedicating resources to another man’s child.

Twin Studies

Twins have a special claim upon our attention; it is, that their history affords means of distinguishing between the effects of tendencies received at birth, and those that were imposed by the special circumstances of their after lives.

Sir Francis Galton

Sir Francis Galton was an extremely influential British scientist and statistician. He developed correlational research and statistical procedures and coined the term “nature versus nurture” (Galton, 1883). In the absence of the ability to manipulate heredity, Galton suggested that the next best thing was to study twins. By observing the behavior of identical and fraternal twins raised in similar or different environments, it was possible to make inferences about the possible roles of heredity and experience in human individual differences.

Figure 9.8 portrays the results for such a study. Correlations are shown for the IQ scores of individuals having different family relationships, some reared together and some reared apart. Since identical twins reared together share both their genes and environments, they would be expected to be most similar and the results bear this out. The lower correlation for fraternal, than identical twins reared together, indicates that heredity also exerts an influence. As indicated previously, intelligent behavior requires that genetic potential be realized through appropriate experience. In the absence of the potential or the appropriate learning experience, the behavior will not appear.

File:Correlation coefficient of intelligence quotients compared with genetic similarity.png

Figure 9.8 Correlation between family relationship and IQ.

Nature/Nurture and the Big Five

Based on McCrae’s previously cited cross-cultural research findings, there is every reason to believe that members of the Nukak tribe differ in regard to the Big Five personality dimensions. Cross-cultural research indicated the Big Five personality factors are prominent all over the globe. Whenever one observes such similarities across diverse cultural conditions, it suggests a genetic influence. Correlations are stronger for identical (monozygotic) than fraternal (dizygotic) twins on each of the Big Five personality traits, suggesting a genetic influence (Jang, Livesley, & Vemon, 1996). Buss (1995) has suggested that the variety of interpersonal relationships created by combinations of the Big Five personality traits is adaptive from an evolutionary perspective. The potential for such variability in social groups permits adapting to diverse cultural norms and contingencies of reinforcement and punishment. Thus, even though individual personalities can be described in terms of the same five traits for every culture, there will be overall cultural differences relating to specific adaptive demands. For example, extroversion may be more characteristic of individualistic cultures such as the United States, and introversion more characteristic of more collectivist cultures, such as China.

Attempts have been made using advances in MRI technology to determine if biological factors underlie the Big Five personality factors. Differences in the volume of brain regions were found for four of the five factors: conscientiousness, extroversion, agreeableness, and neuroticism. Conscientiousness was related to the brain region associated with impulse control, planning, and problem-solving. Extraversion is associated with a brain region related to adaptive learning requiring the determination of the likelihood of reward and punishment in different circumstances. Agreeableness was associated with regions involved in processing information and drawing inferences regarding the behavior of others. These regions appear related to such desirable qualities as empathy and altruism. Neuroticism was associated with brain regions involved in self-evaluation and the experience of negative emotions, often in dangerous and punishing situations (DeYoung, Hirsh, Shane, Papademetris, Rajeevan, N., & Gray, (2010).

Contemporary Temperament Theory

Do you have or know a pet dog? Do you think dogs have different personalities or temperaments? As mentioned previously, contemporary psychologists have returned to considering the possibility that humans display different temperaments similar to the Big Five personality factors very early in life (Bates, & Wachs, 1994; Kagan,1994; Komsi, Räikkönen, Pesonen, Heinonen, Keskivaara, & Järvenpää, et al., 2006; Rowe & Plomin, 1977). This recent interest appears to have been stimulated by the suggestion that other animals display temperaments similar to humans. Behaviors suggesting fearfulness, affiliativeness, aggressiveness, and impulsivity can be observed in mice, cats, dogs, and chimpanzees, as well as humans (Diamond, 1957; Jonas & Gosling, 2005). Whenever one observes similar behaviors in humans and other animals, there is the likelihood that the behavior is transmitted genetically and has adaptive or reproductive value. Simple reflexes such as eye blinks and withdrawal responses are obvious examples. Other examples described previously include the tendency to become active when deprived of food or water, acquired taste aversion, and the tendency to be more influenced by short-term as opposed to long-term rewards. Temperament theory suggests that certain aspects of human personality are inherited and have evolutionary survival value.

Buss & Plomin (1975) expanded upon Diamond’s work, attempting to clarify and delineate the criteria for defining temperament. To heritability, they added the requirement that the behavior appear early in life and display continuity throughout development. Following is a list of additional, more recently suggested criteria for determining temperamental differences in children (Zentner & Bates, 2008).

  • Individual differences in normal behaviors pertaining to the domains of affect, activity, attention, and sensory sensitivity
  • Typically affects response intensities, latencies, durations, thresholds, and recovery times
  • Appearance in the first few years of life (partial appearance in infancy, full expression by pre-school age)
  • Counterpart exists in primates as well certain social mammals (e.g., dogs)
  • Closely, if complexly linked to biological mechanisms (e.g., neurochemical, neuroanatomical, genetic)
  • Relatively enduring and predictive of conceptually coherent outcomes (e.g., early inhibition predicting internalizing, early difficultness externalizing disorders)

Buss and Plomin (1975) initially concluded that emotionality (similar to Diamond’s fearfulness), activity (similar to aggressiveness), sociability (similar to affiliativeness), and impulsivity fulfilled their three criteria. Subsequently, they observed that impulsivity often does not appear until the child enters school, and reduced their list of basic temperaments to three. Jerome Kagan, one of the founders of American developmental psychology, conducted longitudinal research, assessing the same children over extended periods of time. He concluded that infants may be described more simply as having inhibited or uninhibited temperaments. Inhibited and uninhibited infants display the behaviors characteristic of the avoidant and secure attachment styles described by Ainsworth and Bell (1970) in the previous chapter. The inhibited child appears timid and fearful and is unlikely to explore the environment. The uninhibited child appears more secure and calm and is more likely to explore, even in the absence of the parent or caretaker. In an initial study (Kagan, Reznik, & Snidman, 1988), it was found that two-year-olds who were timid or secure in the presence of strangers (i.e., inhibited), displayed the same tendencies at seven years of age. These behavioral patterns were linked to sympathetic arousal of the cardiovascular system for the inhibited (fearful child). The uninhibited, calm child displayed more relaxed, parasympathetic cardiovascular activity. A follow-up study (Kagan and Snidman, 2004) followed four-month-olds until they were seven-years-old. Initially, the infants’ motor activity and crying were observed when they were presented with unfamiliar visual stimuli, sounds, and smells. Approximately 20 percent of the children were “high reactive” (i.e., displayed excessive motor behavior and crying) and 40 percent were “low reactive (i.e., displayed little agitation or crying).

Describing children as having inhibited or uninhibited temperaments fulfills the expanded list of criteria. A benefit of the distinction between inhibited and uninhibited temperaments is that it can be diagnostic for potential developmental problems and prescriptive for remedial interventions. For example, high-reactive infants were found to be three times as likely as low-reactive infants to develop anxiety disorders by the age of seven (Kagan, Snidman, Zentner, & Peterson, 1999). As we saw in Chapter 5, there are effective direct and indirect learning procedures for the treatment of fear and anxiety, including in vivo and imaginal desensitization. In more severe instances, it may be necessary to prescribe medications (see Chapters 11-12).

It should not be concluded that a particular temperament necessarily results in a specific personality profile. Kagan and Snidman (2004) describe how socioeconomic status, culture, and parental styles can result in many variations, within constraints, for children with inhibited or uninhibited temperaments. In fact, often problems arise, not so much because of a specific temperament but because of a mismatch between the child’s temperament and environmental demands. It has been found to be effective to train parents and teachers to adjust their approaches to be more consistent with a child’s temperament (McClowry, Rodriguez, & Koslowitz, 2008). Kagan and Snidman (2004) also suggest being careful about assuming that all temperamental effects are genetic. For example, it has been concluded that the prenatal environment of the fetus may impact upon a child’s developing temperament (Werner, Myers, Fifer, Cheng, Fang, & Allen et al., 2007).

Indirect genetic Influences

You are familiar with the concept of self-fulfilling prophecy. It is an example of an indirect influence on behavior. In this instance, labeling an individual results in others treating the individual in accord with the label. There are other powerful examples of indirect influences on behavior, including those resulting from genetic characteristics. You might be asking, how can a genetic influence be both direct and indirect? Perhaps the most obvious and most important example is your sex. If you inherited a Y-chromosome, you have a higher level of the male hormone testosterone. Testosterone levels are related to activity level and aggression in both human males and females (Pasterski, Hindmarsh, Geffner, Brook, Brain, & Hines, 2007). Testosterone effects are examples of a direct influence of genetics on behavior. How active and aggressive one is will affect how others react. These reactions constitute indirect effects on behavior.

There are many other indirect effects of being born female or male. Parents treat girls and boys differently from birth (Witt, 1997). Girls are likely to be dressed in pink or soft pastel colors and boys in blue or other dark colors. Parents are gentler with girls and more likely to play roughly with boys. Girls are frequently given dolls and kitchen-related toys whereas boys are given action-oriented toys such as balls and cars.

Personality as Adaptive Learning

Let’s return to talking about the qualities you consider important for your ideal mate. Congratulations! You have discovered someone whom you consider ideal on the Big Five or Cattell’s 16 Personality Factors. There is one concern, however. The person is allergic to hops and uncontrollably sneezes into your beer. Is that a deal breaker? Temperaments and traits describe personality in terms of broad (perhaps vague) patterns of behavior. Often, we are interested in much more specific behaviors or qualities in our friends and/or romantic interests. Does the person dance well, drive a car, read “good” books, enjoy a good joke, keep from sneezing in your beer? Those emphasizing the role of learning in the development of personality do not consider trait (or temperament) labels to be sufficiently specific to be helpful. In addition, trait labels frequently serve as pseudo-explanations for behavior. Someone is described as sitting alone at a party as the result of being introverted or as the life of the party as the result of being extroverted. Someone performs well in school as the result of being conscientious or poorly as the result of being unconscientious. Introversion and conscientiousness are not independent variables (i.e., potential causes). Rather, trait labels are generic categories of dependent variables (i.e., behaviors to be explained). For example, introversion can describe sitting alone at a party, not speaking up in school, being quiet when with one’s friends and family, etc. The term “introversion” provides no information concerning why these specific behaviors occur. Psychology always looks to heredity (nature) and experience (nurture) for its explanations.

We previously mentioned the ABCs of control learning: antecedents, behavior, and consequences. Learning theory assumes that complex human behavior, including one’s personality, is acquired through direct and indirect experience. Personality, consistent with the assumptions of evolutionary psychology, consists of adaptations to one’s environmental demands. Adaptation requires learning what the consequences of one’s acts will be under different conditions. Let’s use your pretend child (generically named Jamie) from last chapter to provide an example of the application of learning theory. Your family is visiting relatives for a holiday get-together. Jamie has attended similar get-togethers in the past and is familiar with the newspaper reading habits of two aunts and an uncle. Aunt Lucy is sometimes very resistant to Jamie’s wanting to play with her while at other times she gives in right away. Aunt Rose has a strategy whereby she reads an article from beginning to end and waits for the next incidence of pestering that she knows is coming. After playing with Jamie for a while, she reads another article from beginning to end. Uncle Harry is hard of hearing, which in dealing with Jamie is not altogether a bad thing. He turns down the volume in his hearing aids and reads the newspaper without ever paying attention.

Do you think Jamie will behave the same way toward the aunts and uncle? Or, do you expect different patterns of behavior to emerge resulting from the different ways in which they respond to Jamie? In Chapter 5, we described different intermittent schedules of reinforcement. Aunt Lucy, by providing attention after different amounts of pestering , was implementing a variable ratio (VR) schedule. Aunt Rose’s strategy of waiting until she completed an article, resulted in a variable interval (VI) schedule with the length of each interval determined by how long it took her to finish each article. Uncle Harry, by not paying attention at all, was applying the extinction procedure. After repeatedly being exposed to these contingencies, Jamie would be expected to respond with the characteristic pattern associated with each reinforcement schedule: continuously pestering Aunt Lucy at a very high rate; consistently pestering Aunt Rose at a moderate rate; and not pestering Uncle Harry at all. The described scenario with Jamie is an example of a multiple-schedule, whereby different reinforcement contingencies are reliably associated with distinct antecedent stimuli (the aunts and uncle in this case).

Culture and Socialization

Children behaving similar to Jamie frequently become identified as “pests.” This could result in the circular reasoning characteristic of pseudo-explanations. One might reason that Jamie bothers adults because of being a pest rather than being labeled a pest because of bothering adults. This could result in the failure to consider alternative explanations for Jamie’s behavior (i.e., the different patterns of attention provided by adults) and in a self-fulfilling prophecy whereby Jamie is treated in a particular way because of being considered a “pest.” The example of Jamie indicates that trait labels, in addition to not being sufficiently specific to be helpful, are not explanatory (i.e., they provide no information about genetic or experiential causes of behavior).

In addition, trait labels are inaccurate and misleading as descriptions of behavior. Describing an individual as a “pest”, or as “aggressive”, or as “extroverted” implies cross-situational consistency. That is, in the same way that disease related symptoms occur wherever you are, characteristic trait behaviors would be expected under all conditions. Being a “pest” implies that Jamie is always a pest. Yet, this is not the case. Jamie’s pestering varies depending upon who is sitting in the easy chair. Similarly, college students agree that they can be the life of the party with one group of friends while being quiet and withdrawn with others. Does it make sense to describe an individual as extroverted or introverted if both behavior patterns occur? The example of Jamie reveals how a multiple-schedule, adaptive learning analysis of human personality can accurately describe and explain situational inconsistencies of conduct. It also helps us understand what we mean by culture and socialization. Culture refers to consensually agreed-upon rules relating situations (i.e., antecedents), behaviors, and consequences. Socialization is the implementation of these rules in parenting, schooling, and other inter-personal relations. For example, in some cultures children are encouraged to look adults in the eye when they are talking. In other cultures, this same behavior is considered rude.