dozens of scales intended to measure depression and others to assess
closely related concepts such as loneliness and hopelessness. Many ofthese scales are technically excellent instruments, but their sheer num -
ber makes it difficult to comprehend the scope of personality variables.
In an attempt to bring some order to the field, several researchers
have proposed trait systems, sometimes based on elaborate theories,sometimes simply reflecting a judicious choice of traits. Most have de -
veloped personality inventories to measure simultaneously all the traits
in the system and thus provide a fuller personality profile than any sin -
gle scale could give.
Jung’s (1923/1971) theory of psychological types became the basis
of many instruments. In particular, scales to measure the two Jungianattitudes of Introversion and Extraversion quickly became popular. Inone of the earliest applications of factor analysis to personality re -
search, J. P . Guilford and R. B. Guilford (1934) analyzed measures of
Introversion–Extraversion and found that several different traits wererepresented. J. P . Guilford continued his factor analytic studies ofpersonality and eventually developed an inventory of 10 traits, theGuilford–Zimmerman Temperament Survey , or GZTS (J. S. Guilford,W . S. Zimmerman, & J. P . Guilford, 1976). Another factor analyst, HansEysenck, noted that Extraversion was one of two fundamental dimen-sions that recurred in analyses of many personality inventories. The sec-ond dimension was emotional instability or maladjustment; because itwas seen most clearly in individuals traditionally diagnosed as neurot-ics, he called this dimension Neuroticism. Later H. J. Eysenck and S. B.G. Eysenck (1975) added a third dimension, Psychoticism, to their listof basic personality dimensions. In addition to Introversion–Extraversion,Jungian psychology calls attention to two other contrasts: Sensationversus Intuition, and Thinking versus Feeling. The Myers–Briggs T ypeIndicator, or MBTI (Myers & McCaulley , 1985), measures these, as wellas a contrast between Judging and Perceiving.
Henry Murray , whose 1938 volume Explorations in Personality is
one of the classics of the field, was a psychodynamic theorist whoviewed motivation as the key to personality . He and his colleagues at theHarvard Psychological Clinic identified a list of needs or motives theyconsidered necessary for a reasonably complete description of the indi -
vidual’s personality . Needs for achievement, affiliation, and nurturance
are among the list of 20 or so needs. Many instruments have been cre -
ated to measures these needs, of which perhaps the best is Douglas Jack -30 PERSONALITY IN ADULTHOOD