Everyday conceptions of traits
The idea of personality traits may be as old as human language itself. Aristotle (384–322 BC), writing the Ethics in the fourth century BC, saw dispositions such as vanity, modesty and cowardice as key determinants of moral and immoral behaviour. He also described individual differences in these dispositions, often referring to excess, defect and intermediate levels of each. His student Theophrastus (371–287 BC) wrote a book describing thirty ‘characters’ or personality types, of which a translator remarked that Theophrastus’s title might better be rendered ‘traits’ (Rusten, 1993). Basic to his whole enterprise was the notion that individual good or bad traits of character may be isolated and studied separately.
Contemporary English is replete with terms used to describe personal qualities. Table 1.1 shows some examples: the five words rated by American college students as the most and least favourable words in Anderson’s (1968) survey of 555 personality terms, together with five words given a neutral rating. Allport and Odbert (1936) identified almost 18,000 English personality-relevant terms; more words than Shakespeare used! Nouns, sentences and even actions may also have personality connotations (Hofstee, 1990). The language of personality description permeates our everyday conversation and discourse.
Everyday conceptions of personality traits make two key assumptions. First, traits are stable over time. Most people would accept that an individual’s behaviour naturally varies somewhat from occasion to occasion, but would maintain also that there is a core of consistency which defines the individual’s ‘true nature’: the unchangeable spots of the leopard. In other words, there are differences between individuals that are apparent across a variety of situations.We might expect a student we have noted as a ‘worrier’ to be unusually disturbed and worried in several different contexts such as examinations, social occasions and group discussions. Stability distinguishes traits from more transient properties of the person, such as temporary mood states. Second, it is generally believed that traits directly influence behaviour. If a person spontaneously breaks into cheerful song, we might ‘explain’ the behaviour by saying that he or she has a happy disposition. Such lay explanations are, of course, on shaky ground because of their circularity. Aristotle suggested a more subtle, reciprocal causal hypothesis: that it is through actions that dispositions develop, which in turn influence actions. It is by refraining from pleasures that we become temperate, and it is when we have become temperate that we are most able to abstain from pleasures. (Thomson’s, 1976, translation of the Ethics, 1104a: 33–35) One of the major tasks for a scientific psychology of traits is to distinguish internal properties of the person from overt behaviours, and to investigate the causal relationships between them. To avoid circularity, it is essential to seek to identify the underlying physiological, psychological and social bases of traits, which are the true causal influences on behaviour.
The beginnings of trait theory
In addition to minimally adequate statistical procedures for dealing with traits, and some conception of where to begin to search for trait stimuli, there was a contemporaneous theoretical development of trait psychology. In part, this theoretical development was driven by an awareness of the fact that trait psychology was perforce beginning with commonsense terms in everyday use. Allport (1937) commented that: To use trait terms, but to use them cautiously, is, then, our lot. Nor need we fear them simply because they bear the age-long sanction of common sense. Carr and Kingsbury’s article from 1938 addressed many core issues of trait psychology at a conceptual level. They emphasised the predictive nature of traits, i.e., knowing the traits of an individual was predictive of that person’s likely future behaviour. Moreover, they articulated the notion that traits were not directly observable – traits may only be inferred from behaviour. This continues to be the view of prominent trait theorists. For example, McCrae et al. (2000, p. 175) stated, Traits cannot be directly observed, but rather must be inferred from patterns of behaviour and experience that are known to be valid trait indicators.
Carr and Kingsbury emphasised the need for trait scales in order to compare individuals on a given characteristic. They lamented the blind progress of trait psychology and its lack of ‘principles of orientation in reference to the concept’. This last continued to be one of the most contentious issues in the theory of traits (Pervin, 1994). One of their closing comments is ironic when one reflects on the pre-eminence of the dimensions of neuroticism (emotional stability) and introversion–extraversion today, We may note that abnormal and clinical psychology have evinced no interest in the popular traits, but have developed a new set of traits that are supposed to possess a distinctive value for their purposes. We refer to such traits as introversion and extraversion, submission and ascendancy, emotional stability, mal-adjustment, and integration. Perhaps a systematic psychology should likewise be concerned with the development and study of a set of new traits that are relevant to its purposes.
Perhaps the most comprehensive contribution to the conceptual development of trait psychology, and of personality psychology more generally, is Allport’s (1937) book, Personality: a Psychological Interpretation. Much of present-day trait psychology may be considered as empirical footnotes to Allport’s chapters 9–12, where he laid out the tasks for, and difficulties facing, the personality psychologist. 12 The nature of personality traits
Allport’s resounding ‘Resume of the Doctrine of Traits’ began with the famous sentence, In everyday life, no one, not even a psychologist, doubts that underlying the conduct of a mature person there are characteristic dispositions or traits. In addition to the common traits that are emphasised in the present book (indicative of the nomothetic approach), Allport also emphasised those traits which are more specific to individuals and that are not prone to distribute normally in the population (indicating that an idiographic approach is necessary also). Allport’s account of traits was able to embrace many disparate approaches. Thus, in addition to accommodating differential psychologists, his overall definition of traits moved Murray (1938) to indicate that his ‘needs’ – identified by a depth psychology approach using biographical interviews and projective tests – could also be conceptualised as traits, such as need for achievement.