The Lexical Base of the Five-Dimensional Model 235THE LEXICAL BASE OF THE
FIVE-DIMENSIONAL MODEL
A basic motive of researchers involved in the 5-D paradigm
is to give a systematic and comprehensive, or at least repre-
sentative, account of personality traits. An accompanying
notion is that the field is characterized by a proliferation
(John, 1990) of concepts and instruments, which frustrates
the progress of the science of personality. The signature of
the 5-D paradigm is empiricist and, in a sense, antitheoreti-
cal: If theorists, in this context, are individuals bent on dis-
seminating their idiosyncratic concepts of personality, then
their collective but uncoordinated action is responsible for a
chaotic state of affairs in which thousands of unrelated con-
cepts and their operationalizations form a market rather than
a science. The 5-D conception is thus a taxonomy intended
to end all idiosyncratic taxonomies.
To lift personality out of its chaotic state, an Archimedean
point was needed. The most obvious candidate for a point of
departure at the descriptive or phenotypic (Goldberg, 1993b)
level is the lexicon. Like genetics, it provides a finite set of
elements on the base of which a taxonomy may be built and
proliferation may be counteracted. This section contains a
discussion of the lexical point of departure, its variations,
and its consequences. An analysis of the different shapes of
the Factor V and their operational antecedents serves as an
illustration.
The Lexical Axiom
What is usually referred to as the lexical hypothesis is more
like an axiom. It states that people wish to talk about what-
ever is important and that the terms in which they talk may be
found in the lexicon. The first and central part of that state-
ment is not a hypothesis that is subject to empirical confirma-
tion or disconfirmation; it introduces a heuristic that may or
may not appear to be fertile. The second part is definitely
false as no dictionary is ever complete; however, it is un-
problematic because most dictionaries contain far more
words than most people care to use or even understand, and
hardly if ever omit common terms.
An objection that is seldom voiced although it is obvious
enough is that the reverse of the lexical axiom does not nec-
essarily hold true: People may well be talking about unim-
portant things most of the time. There is something to be said
for the idea that the language of normal personality does
not serve much of a purpose. However, PCA (see the
next section) capitalizes on redundancies among variables.
That method thus retroactively introduces a corollary of the
lexical axiom, namely, that redundancy is indicative of real
importance. For playful purposes, we may seek rare and
sophisticated terms or combinations of terms; at the level
of common components, however, we mean business. Of
course, this corollary, in its turn, may or may not be judged
credible.
A reverse objection is that common language is not subtle
enough for scientific purposes. One may philosophize at
length about this proposition, which is as metaphysical as the
lexical axiom itself. The historic rebuttal, however, was
delivered by Digman (1990; Digman & Inouye, 1986), who
recovered the Big Five structure in questionnaires, that is, in
instruments designed by experts. In a similar vein, I (Hofstee,
1999) asked 40 clinicians to score a prototypical personality
disorder with which they were familiar on the items of
the Five-Factor Personality Inventory (FFPI; Hendriks,
Hofstee, & De Raad, 1999). These items do not contain
any technical terms or pathological content. Nonetheless,
very distinct and extreme profiles in 5-D terms resulted,
again indicating that expert categories may be well repre-
sented by ordinary language.
In principle, the lexical approach both reflects and fosters
a lay definition of personality; in practice, however, the
effect seems to be slight. Thus, at low conceptual costs 5-D
research has succeeded in bringing a considerable measure of
order to the anarchy of phenotypic traits. Any serious investi-
gator proposing a new trait concept would now be well ad-
vised to investigate whether it has incremental validity over
an optimal linear combination of the five factors; existing
concepts are better understood in that framework. An exam-
ple is typical intellectual engagement (Goff & Ackerman,
1992), which appears to be a label for a mixture of Factors V
and III; another is the familiar concept of sociability, blend-
ing Factors I and II. As I argue later, there is nothing against
using dedicated labels for blends if they are distinguished
from variables that do carry considerable specific variance.
But even if taken liberally, the five factors represent a taxo-
nomic breakthrough, part of which may be credited to the
lexical approach.Operationalizations of the Lexical ApproachThere is no unique and cogent operationalization of the lexi-
cal approach. It pertains to single personality-relevant words,
under the tacit supposition that words do not interact, so that
the meaning of any trait combination can be represented by a
linear function of them. That supposition is patently false in
the case of oxymoralike “amiably inimical” or “quietly exu-
berant,” joinings of opposite terms whose meaning cannot be
accounted for in a linear fashion; however, there are reasons
to be wary of such seductions of literary language. In any