Constructing Personality Through Questionnaires 233means of a questionnaire (e.g., Goff & Ackerman, 1992), or
test the maximal introversion of which he or she is capable
(see Riemann, 1997), but neither of these crossovers has ap-
peared to be adequate or promising. Ability and tests of max-
imal performance, and personality and assessments of typical
behavior, are associated in a nonarbitrary manner (Hofstee,
2001).
Are Questionnaires There to Stay?
The prime product of the 5-D paradigm consists of question-
naires, including most notably the Neopersonality incen-
tives-PI-R and NEO-FFI (Costa & McCrae, 1992), and
includes many other questionnaires and trait adjective lists;
the model has thus given a significant boost to the question-
naire construction of personality. I have argued in brief that
the relation between personality traits and the questionnaire
operationalization is intimate. Should one be happy with
the prospect of such an essentially monomethod definition of
personality, and if not, can alternatives be foreseen?
Asking questions to third persons in order to assess per-
sonality implies a social definition of it. Surely, the field has
moved beyond the stage at which personality was deemed to
be merely in the eye of the beholder; cumulative behavior-
genetic research (see, e.g., chapter by Livesley, Jang, &
Vernon in this volume; Loehlin, 1992) has put an end to that
subjective conception of traits. But the dominant conception
of personality remains social in the sense of intersubjective
rather than objective. Buss (1996) made a virtue of this need
by explaining the Big Five as elementary social mechanisms;
for example, Factor III represents the need of the perceiver to
know whether the other person can be depended upon. Most
students of personality, however, would have hesitations with
this subordination of personality to social psychology, espe-
cially if that bondage is a side effect of a dominant opera-
tional approach.
The scientific emancipation of a subjective or intersubjec-
tive concept appears to hinge upon the discovery of objective
indicators that cover the concept well. If we wish to establish
how much of a fever we run, we do not use a Likert scale but
measure it with a thermometer. If we want to gauge an appli-
cant’s intelligence, we apply a test rather than asking ques-
tions to the applicant or even to a number of third persons. If
the latter example is more problematic than the first, that is be-
cause there may be doubt regarding the coverage of the con-
cept of intelligence by an IQ score. In the same vein, one may
have doubts about the thermometer scale as a measure of out-
door temperature and prefer a formula that includes sunshine,
humidity, and wind force. But once a certain level of coverage
is secured, a return to sheer subjectivity would count as re-
gressive. Are adequate objective indicators of personality
traits in sight?
Probably the most promising indicators of personality are
genes. According to estimates based on behavior-genetic
research, genetic patterns will be capable of covering some
40% of the trait variance. That degree of coverage is not
enough; we would not accept a thermometer that is only 40%
valid. But before discarding the prospect, one should realize
that the figure of .4 is heavily attenuated. An indicator need
not and should not predict the error components in subjective
assessments of temperature or extraversion. Heredity coeffi-
cients in the order of .4 should thus be divided by an estimate
of the proportion of valid variance in questionnaire scores.
The first source of error in the self-reports that have almost
invariably been used in behavior-genetic studies of personal-
ity is lack of agreement between assessors. The highest
agreement coefficients between self and other in assessing
personality (Hendriks, 1997; McCrae & Costa, 1987) are in
the order of .7. Unless it is assumed that self is a systemati-
cally better assessor than other or vice versa, that figure may
be taken as an estimate of the rater reliability of a single re-
spondent, and some 30% of the questionnaire variance is
rater error. Second, some 20% of the variance results from
lack of internal consistency of the questionnaire scale, as-
suming alpha reliabilities in the order of .8; and third, a com-
parable error component results from temporal instability.
Taking all these independent sources of error into account,
one is left wondering how the heredity coefficients can reach
.4 at all (Hofstee, 1994a).
The ironic conclusion from this crude analysis of error
components in questionnaire variance is that the perspective
of molecular-genetic diagnosis of personality traits cannot at
all be discarded: It may well appear that whatever valid vari-
ance remains in questionnaire data can be accounted for to a
satisfactory extent by genetic configurations. However, the
analysis also points to the conditions for such a development.
To establish links between genes and phenotypic personality
traits, the assessment of the latter will have to be much more
valid than it has been up to now (see also Bouchard, 1993).
The central element of that program is discussed in the next
paragraphs. Another aspect—optimizing the internal consis-
tency of questionnaire data—is treated in the section on the
linear approach to personality.Definitions of Personality by Self and OthersSelf-report fosters a conception of personality whereby the
individual knows best how he or she is. With self-report