234 Structures of Personality Traits
questionnaires,the situation is more complicated. Standard-
ized questions aim at comparing personalities rather than
capturing unique and emergent characteristics. McAdams’s
(1992) criticism of the Big Five approach as a psychology of
the stranger is correct in that sense (although other phrasings
might be preferred if the value of scientific objectivity is
stressed); it would be even more correct if the emphasis in
Big Five research were on other-report rather than self-
report. Self-report questionnaires embody a discordant blend
of subjective and intersubjective accents.
In preparing an earlier (Hofstee, 1994a) paper on the
topic, I met with unexpectedly ardent arguments in favor of
self-report from prominent American Big Five researchers,
the essence of which is documented in that paper. One argu-
ment pertained to personal secrets, whose content, however,
would not be central to personality in most definitions. (A
person might be said to be secretive, but that trait hardly even
makes sense from the person’s own point of view.) Another
argument was that a person might sit in a corner over a large
number of consecutive parties but still consider himself or
herself to be extraverted, which would be all that counts. In
practice, however, most witnesses would start worrying
whether that person were still in contact with reality (which is
again different from the question about introversion or extra-
version). In the abstract, actors are at liberty to entertain a
subjective definition of personality, but in real life it does not
carry them very far. The intersubjective viewpoint is not
merely a matter of scientific style; it is in touch with what
people think of personality.
If the intersubjective viewpoint is accepted as a proper per-
spective on personality and if idiosyncrasies in self-report are
seen as a source of error among other sources of error, the con-
sequence for personality research and practice is as straight-
forward as it is revolutionary: Multiple assessors are needed to
achieve acceptable reliability and validity; self-reports, being
single by definition, are inevitably deficient. Self is of course
acceptable as an assessor among others; self-ratings might
even contribute more to the common variance than others’ rat-
ings do. But in any case, the road toward an eventual objective,
genetic diagnosis of personality, will have to be paved with
multiple assessors; good intentions will not be enough.
THE FUTURE OF THE
FIVE-DIMENSIONAL MODEL
Will genetic fingerprinting in due time describe personality in
terms of extraversion, agreeableness, conscientiousness,
emotional stability, and some version of Factor V? In other
words, will the 5-D model survive the developments that
most readers may expect to witness in their lifetimes
(whether they like it or not)? At the moment of writing this,
the answer can hardly be unequivocal; even the question may
appear to need rephrasing.
In an extensive reanalysis of several data sets, Saucier
(2002a) found a three-dimensional structure containing
agreeableness, conscientiousness, and extraversion to be
more replicable across samples than a 5-D structure, espe-
cially in peer ratings, which in the present reasoning are more
germane than self-ratings. So we might end up with a subset.
Using a comparable three-dimensional solution, Krueger
(2000) showed that the additive-genetic structure underlying
the Multidimensional Personality Questionnaire (Tellegen,
1982) corresponded closely to the phenotypic structure.
On the other hand, Jang, McCrae, Angleitner, Riemann, &
Livesly (1998) demonstrated that specific factors beyond the
first five have nonzero heritability coefficients.
Even supposing reliable and valid assessments of pheno-
typic personality traits, a routine search for indicators of, for
example, conscientiousness would require enormous samples
just for tracing additive polygenetic effects; for interactions,
the required sizes would rise exponentially (for a discussion
of strategies of molecular-genetic research on personality, see
Plomin & Caspi, 1998). At the turn of the century, attempts to
trace genetic polymorphisms that explain personality showed
the familiar picture of high initial expectations followed by
failing replications (e.g., Herbst, Zonderman, McCrae, &
Costa, 2000). According to a possibly more feasible scenario,
large principal components of personality traits may be ex-
pected to reappear as an aggregate result of studies searching
for single genes to explain specific patterns of deviant behav-
ior (see, e.g., Brunner, Nelen, Breakfield, Roppers, & Van
Oost, 1993). Assuming continuity between the range of nor-
mal behavior and deviant extremes, the aggregate structure of
a large number of such specific patterns would resemble the
5-D structure. In the process, such taxonomies of phenotypic
traits would receive a status comparable to mineralogical
classifications; the chemistry of individual differences would
be located at the DNA level.
Decades ago, Carlson (1971) found that personality was
spelled in either of two ways: social or clinical. The
questionnaire conception of personality is arguably social-
psychometric by its methodological nature. If the genetic
approach becomes dominant, a clinical reconstruction will
regain momentum; individual differences within the normal
range will be seen as mitigations and moderations of person-
ality defects constituting the chemical elements. Meanwhile,
an enormous amount of work has to be done, and 5-D ques-
tionnaires filled out by several third persons and self are
instrumental in that labor.