The Story of Psychology

by Morton Hunt

  Consider the case of Jim Lewis and Jim Springer, identical twins who were separated a month after their birth in 1940 and reared forty-five miles apart in different families in Ohio. They were totally unaware of each other’s existence until 1979, when they were thirty-nine. In that year they met, but not by accident. They had been tracked down by Professor Thomas Bouchard, director of the Minnesota Center for Twin and Adoption Research at the University of Minnesota, who was conducting a study of fraternals and identicals reared apart. Jim Lewis and Jim Springer, except for their clothing, were physically indistinguishable, as are almost all pairs of identicals. Remarkable as this always seems, what was far more remarkable were other similarities. Both men had wives named Betty, were heavy smokers of Salems, drove Chevrolets, bit their fingernails, and had dogs named Toy.

  This sounds as if it had been concocted by a writer for one of those supermarket tabloids filled with accounts of such wonders as babies borne by eighty-year-olds. But the story was not concocted. Of course, some of the peculiar coincidences may have been due to the twins’ living in the same part of the country, others to chance. What was more important was the evidence adduced by psychological testing. Bouchard and his research team put the twins through a battery of personality tests and found their responses and trait scores nearly identical.78

  From 1979 to 1990, Bouchard and his researchers tracked down nearly eighty pairs of identicals and thirty-three pairs of fraternals reared apart (out of some eight thousand pairs in their files), and put each twin through about fifty hours of intensive tests and interviews. For comparative purposes, they did the same with a number of identical and fraternal twins reared together. Statistical analysis of all the correlations within the twin pairs and among these various groups led the team to conclude that about 50 percent of variance in personality is due to heredity.79 (They reported similarly remarkable findings for many other psychological variables, including general intelligence, language ability, social attitudes, homosexuality, substance abuse, and even religious interests.)

  Some other studies in behavior genetics, however, have yielded more modest estimates. John C. Loehlin, of the University of Texas, Austin, recently reviewed a large number of twin studies and found that on the whole the evidence indicated that heredity accounts for about 40 percent of the variance in personality.80 Several studies comparing adopted children to their adoptive mothers and to their biological mothers found only 25 percent of the variance attributable to heredity (although, interestingly, the adopted children resemble their biological mothers more than those who reared them in personality).81

  Clarifying the matter, in 2003 Bouchard and a colleague, Matt McGue, performed a comprehensive review of Bouchard’s and other researchers’ twin, family, and adoption research. Sophisticated mathematical analysis produced cumulative evidence that “genetic influence on personality trait variation is in the 40%–55% range” and that “common (shared) family influence on personality traits is very close to zero.” Nonshared—that is, different—environmental influences account for much or most of the other personality variations, but have been extremely difficult to identify.82

  The figures do not mean that 40 to 55 percent of any individual’s personality results from hereditary influences. Variance refers to the range of differences among people in any trait or set of traits. Data from Bouchard’s center show, for example, that if a group of adults range in height from, say, four feet to seven feet, 90 percent of that span of differences is due to heredity, 10 percent to environment. Similarly, the twin studies mean that 40 to 55 percent of the range of personality differences among any group of people are of hereditary origin. This may explain why Americans have so many more variations in personality than the members of a more genetically homogeneous population, like the Japanese.

  The findings of behavior genetics yield new understanding on a theoretical level—a level very different from that which interests most personality psychologists, namely, insight into the emotions and social relations involved in personality, and ways of testing and influencing them. It is even possible to see behavior genetics as diminishing the hope that psychology can improve the quality of human life, since to the degree that personality is hereditary in origin, it is not amenable to parental or social influence, therapy, or any other potentially controllable environmental factor. Many psychologists, therefore, including those in the field of personality, consider the findings of behavior genetics valuable as science but of no benefit in practice. What matters to them is the rest of variance in personality—the extent to which it can be influenced for better or worse.

  Late Word from the Personality Front

  Personality is no longer the most prominent field of psychology, not because it has shrunk in size but because by a generation ago certain newer fields had expanded and become the foci of attention. Also, as in any mature field of science, many personality researchers now churn out overspecialized studies of minutiae; happily, some others are still doing expansive and exciting work.

  Among the more interesting developments in the field has been the study of the influence of personality on “well-being” (the general sense of contentment) in the middle and later years. Paul T. Costa and Robert R. McCrae, working with people enrolled in the Baltimore Longitudinal Study of Aging, a long-running research project of the National Institute on Aging, found that extraverts, who score high on such traits as sociability, general activity, and “ascendance” (similar to dominance), were happier in midlife and beyond than most introverts. They also found that people who score low on neuroticism adapted better to the changes of middle age and old age than people who score high on neuroticism (measured by such traits as chronic anxiety, hostility, self-consciousness, and impulsiveness). The latter were likely to see the problems of middle age as a crisis, worry about their health, be frustrated and disappointed by retirement, and be at risk for depression and despair.83

  What can one do to counteract such personality handicaps? Costa and McCrae suggested that psychotherapy could help, but to a limited extent, since the data of the Baltimore and other studies indicated that personality traits are relatively stable in adult life. Still, they said that even a modest improvement in well-being is as worthwhile as a modest improvement in the control of a serious physical disease.

  Physical diseases of many kinds, according to much recent research, originate in or are exacerbated by certain traits of personality. Two important studies, appearing in 1975 and 1980, produced survey evidence that people with the so-called Type A personality (competitive, striving, hostile, and driven) are likely to develop coronary heart disease. Many later studies of the matter somewhat qualified but did not negate the finding.84

  More generally, Martin Seligman and his colleagues Christopher Peterson and George Vaillant offered evidence in 1988 that one’s explanatory style affects one’s health. On the basis of data yielded by a thirty-five-year longitudinal study of Harvard graduates, they concluded that people who customarily have a pessimistic or negative interpretation of life fall ill more often than optimists and have shorter life expectancies. They saw psychotherapy—particularly short-term cognitive therapy—as a useful antidote. As we have already seen, Seligman has gone on to develop the doctrine that cognitive training can convert a negative explanatory style to a positive one, with beneficial effects on physical and mental health, this being the core of his present system of Positive Psychology.85

  Hans Eysenck, reviewing the results of a number of personality and health studies, including some he himself conducted, said that the “dramatic results…point to a very strong connection between certain personalities and specific diseases.” He noted that many physicians have associated cancer-proneness with the inability to express anger, fear, or anxiety, and with feelings of hopelessness, helplessness, and depression, and that longitudinal studies show many of the same traits to be associated with heart disease. On the basis of these data, Eysenck and a collaborator, a Yugoslavian psychologist named Ro
nald Grossarth-Maticek, conducted an experiment in preventive medicine, with the following extraordinary results:

  [We] tried to use behavior therapy to teach cancer- and heart disease–prone people to express their emotions more readily, to cope with stress, to wean them of their emotional dependencies, and to make them more self-reliant. In other words, we taught them to behave more like the healthier personality types.

  100 people with cancer-prone personalities were divided into two groups: 50 who received no therapy and 50 who did receive it. After 13 years, 45 people who got therapy were still alive. Only 19 were alive in the no-therapy group.

  We tried a similar experiment with 92 heart disease-prone people, divided into therapy and no-therapy groups. Here too there were marked differences 13 years later, with 37 people surviving with therapy and 17 surviving without it.86

  One can only wonder why these experiments have not been replicated or emulated.

  Trait theory, still the guiding view in personality research, has continued to mature, chiefly in the form of the “Big Five model” of trait theory.

  For many years a number of researchers sought to look even deeper into factorial structure than Cattell did and to identify a smaller, more comprehensible, and more fundamental set of factors than his sixteen. Three decades ago, some of them, reworking Cattell’s correlation data, said they could find evidence of five superfactors. Over the years others have found one or more of the same five, in assorted guises, when they put other widely used personality inventories through the statistical wringer. By the 1990s, most personality psychologists had come to agree that the Big Five are the basic dimensions of personality.87 Since then, different researchers have modified some of the factor names, but the Big Five are the basis of current trait theory. They are:

  —Extraversion, the factor some personality inventories list under such related labels as sociability, activity, and interpersonal involvement.

  —Neuroticism, or, in the terminology of other studies, emotionality, emotional stability, and adjustment.

  —Openness to Experience, also identified as inquiring intellect, intelligence, and “intellectance” (an unnecessary neologism that, fortunately, has not caught on).

  —Agreeableness, also appearing as likability, altruism, trust, sociability, and so on.

  —Conscientiousness, or dependability, superego strength, and restrained self-discipline, among other aliases.

  These, according to present thinking, are the crucial and governing personality factors; the multitude of specific traits that account for the richness and variety of human personality are branches and twigs of these five trunks. Although these superfactors blur rather than focus the vision—imagine Hamlet, Lady Macbeth, or Lear described in terms of the Big Five—they offer researchers and clinical psychologists a set of proven dimensions along which to construct personality research designs and organize the data of whatever personality tests they use clinically.88

  Another aspect of the field’s maturing is the resolution of the “consistency paradox”: although individuals have measurable traits and recognizable personalities, the behavior of any individual in a particular situation is a far from certain indication of how he or she will behave in others. The man who is brave under enemy fire may be cowardly in conflict with his wife; the woman who is a pillar of her church may, in her role as a company treasurer, plunder company funds to support a lover; the model family man and Little League dad may have a second wife elsewhere or be a closet public-lavatory homosexual.

  Because of such cross-situational inconsistency, for years some psychologists attacked trait theory as having little validity. But more precise recent research data have led to a sensible resolution of the argument: the more similar the situations, the more consistent a person’s behavior; the less similar, the less consistent. As Walter Mischel of Columbia University, a leading personality researcher and former critic of trait theory, has written:

  The data … do not suggest that useful predictions cannot be made. They also do not imply that different people will not act differently with some consistency in different types of situations… The particular classes of conditions or equivalence units have to be taken into account much more carefully and seem to be considerably narrower and more local than traditional trait theories assumed.89

  The latest word on consistency and the prediction of behavior strikes a different note, but one that is good news: personality traits do tend to change over the life course—most of them for the better. Using a six-factor variant of the Big Five, a meta-analysis (a pooling of the mean changes reported in ninety-two studies of a total of 50,120 people) showed that on average, there is improvement in four of the six “trait domains” throughout middle and old age. These are the findings in graph form (the vertical dimension measures d values, a statistic expressing average differences from the norm):90

  FIGURE 18

  Cumulative d scores for each trait domain across the life course (adapted from Brent W. Roberts et al., “Patterns of Mean-Level Change in Personality,” Psychol. Bull. 132, Jan. 2006: 15, by permission)

  Still another late development of the field is the winding down of the old quarrel between situationists and dispositionists. Most psychologists are now inclined toward the interactionist view that any given piece of behavior results from the interaction of the situation with the individual’s personality. Similarly, the ancient debate as to whether personality is innate or learned is yielding to the interactionist view. Some psychologists still talk as if parents, peers, social class, and other environmental influences are the only significant determinants of personality; some as if our behavior, like that of most other animals, is largely programmed by our genes. But increasingly, psychologists see the personality and behavior of the individual at every point in life as the outcome of the interaction between his or her innate temperament and all the experiences he or she has had up to that point.

  This is a complex concept. Hereditary influences and environmental influences do not merely add up in personality but, like chemicals joining in a compound, interact to form something different from either, which then interacts differently with subsequent experiences. This is the core concept of development, the field of psychological studies to which we turn next.

  * It is now called the Institute of Personality and Social Research, and its goals have become much broader.

  † In a still later version, the CPI has twenty-eight scales. They measure dominance, capacity for status, sociability, social presence, self-acceptance, independence, empathy, responsibility, socialization, self-control, good impression, communality, well-being, tolerance, achievement via conformance, achievement via independence, intellectual efficiency, psychological-mindedness, flexibility, detachment, norm favoring, realization, managerial potential, work orientation, anxiety, and three measures of masculinity-femininity.

  * If these were actual Rorschach blots, each would be on a separate card.

  * The original goal of the Institute for Personality Assessment and Research at Berkeley was to further develop and test the OSS assessment method. That goal was abandoned after a time.

  TWELVE

  The

  Developmentalists

  “Great Oaks from Little Acorns Grow”

  —English proverb

  Many people, when they think of a scientist at work, picture a stereotype: the aproned chemist pouring a fuming liquid into a flask, the cell biologist peering through a microscope, the khaki-clad paleontologist brushing away earth to reveal an ancient bone. But no such image exists of the psychologist at work; psychology is an aggregation of sciences, each with its own mise-en-scène. Even the specific fields within psychology are highly diversified, and none more so than developmental psychology. For instance:1

  —A white-coated technician holds the head of an unhappy laboratory rat while an assistant deftly pries apart the lids of its left eye and inserts a tiny opaque contact lens.

  —A young woman, very pregna
nt, lies on a table; a few inches above her abdomen is a loudspeaker through which her own voice, previously recorded, recites a two-minute poem.

  —A four-month-old baby is propped up and facing a flashing light; a researcher covertly watches the baby’s face. The light flashes regularly for a while, then flashes less often.

  —An eight-month-old boy sits before a miniature stage; a researcher, hidden behind it, pushes a toy dog into view and just as the baby is about to reach for it draws a curtain, hiding the dog.

  —A man kneels down next to a five-year-old boy playing with marbles and says, “I used to play a lot but now I’ve quite forgotten how. I’d like to play again. Let’s play together. You teach me the rules and I’ll play with you.”

  —A young mother, on the floor next to her year-old daughter, suddenly pretends she has hurt herself. “Oh! Ooo! It hurts!” she cries out, clutching her knee. The little girl reaches out as if to pat her, then bursts into tears and hides her face in a pillow.

  —In a small office, a psychologist holds up a green poker chip and says to the ten-year-old girl seated on the other side of the desk, “Either the chip in my hand is red or it is not yellow. True or false?” She promptly says, “False.” Later that day he does the same with a fifteen-year-old girl; she thinks a moment, then says, “True.”

  —A woman researcher plays a tape-recorded scene for a dental student. In it, a Mrs. Harrington, new in town, goes to a dentist for the first time. He says that some of her expensive crowns are defective and cannot be repaired, and that she has advanced periodontal disease, which her previous dentist did nothing about. Mrs. Harrington is upset and disbelieving. The researcher stops the tape and asks the student to assume the role of the dentist and deal with the situation.