Validity Scales
The studies in Table 4 begin in the 1980s. Until that time there had
been relatively few studies comparing self-reports and observer ratings.Ratings are cumbersome to obtain, because raters must be identified,contacted, and persuaded to participate, and because some individualsmay be unable or unwilling to provide the names of suitable raters. Re -
searchers and clinicians have preferred the convenience of self-reports,
even if they did not trust them. Consequently , a major tradition inpersonality assessment has sought ways to determine the validity ofself-reports using special validity scales designed to outwit defensive ordishonest test takers, as a lawyer tries to trap a lying witness in a contra -
diction. Despite extraordinary efforts and ingenuity , however, it is far
from clear that any of these scales really works—probably because mostself-reports are reasonably honest to begin with.
Perhaps the most common strategy for creating validity scales was
used by Edwards (1957), who had judges rate the social desirability ofitems on the Minnesota Multiphasic Personality Inventory (MMPI), andselected a set of highly evaluative items. People who wished to make agood impression would answer yesto the desirable items and noto the
undesirable ones. By summing the number of such responses, test tak-ers could be assigned a social desirability score. High scores were con-sidered by many psychologists as grounds for throwing out the test. An-other MMPI scale, the Kscale, was designed to assess defensiveness,
and scores on the psychopathology scales were “corrected” by adding afraction of the Kscale score (McKinley , Hathaway , & Meehl, 1948). In
theory , this addition compensated for the defensive denial of psycholog -
ical problems.
In practice, however, these approaches are very problematic. Log -
ically , a high score on a social desirability scale might result from an
attempt, conscious or unconscious, to make a good impression; but itmight also result from honest answers by truly well-adjusted, agreeable,and conscientious people. It is desirable to be honest, and liars mightfalsely claim to be honest if asked—but truly honest people would, too!A claim of honesty is inherently ambiguous.
Crowne and Marlowe (1964) believed they had a solution to this
problem: They wrote items that would almost never be literally true,such as “Before voting, I thoroughly investigate the qualifications of allcandidates.” They reasoned that someone who answered yesto many44 PERSONALITY IN ADULTHOOD