Just yesterday I wrote about the lexical hypothesis in personality psychology. Even if there are now some researchers proposing a six-factor general personality trait theory, the Big Five (or the OCEAN model: openness, conscientiousness, extraversion, agreeableness, and neuroticism) is probably the most popular general personality (trait) theory by far. Among the Big Five theorists, there is a group led by Paul Costa and Robert McCrae who have somewhat dissociated from the lexical origin of the Big Five and in their more recent writings propose that the Big Five are not only descriptive terms, but biologically based “basic tendencies” (e.g. in McCrae, Costa, Ostendorf, Angleitner, Hrebickova et al., 2000)¹. However, they do not really explain what “basic tendencies” might mean; instead they put forward evidence for cultural generalizability and long-term stability mainly of questionnaire scores. The argumentation is kind of backwards: They say, “look, the questionnaire scores are cross-culturally and intraindividually stable. They must be biologically based”. This is in itself a very weak argument; one might put forward all kinds of objections like that the long-term stability does not really tell us about something to be biologically based, and the cross-cultural generalizability has been heavily disputed, see e.g. here.
Lisa Pytlik Zillig, Hemenover and Dienstbier (2002) have explored another line of evidence against the “basic tendencies” claim of Costa-McCrae theorists. Instead of meeting them on their own grounds, Pytlik Zillig et al. simply took several Big Five inventories (questionnaires and adjective lists) and analyzed the content of the items of these inventories. They tried to classify the items into one of three categories: how much does an item describe affects, behaviors, and cognitions? (the distinction of affect, behavior, and cognition is quite common in psychology; e.g. there are some models of attitudes that assume an attitude has something of all three, an [evaluative] affective component, a behavioral component [how does one react], and a cognitive, non-evaluative component).
The results are somewhat disappointing for the “basic tendencies” idea: across different inventories and across different groups of raters, items for the Big Five factors differ systematically with regard to how much they reflect affect, behavior, and cognition. Most striking is the difference between items assumed to assess neuroticism vs. items for conscientiousness: where items for the former are mainly (60-90%) about affects, items for the latter are mainly about behaviors (again 60-90%), and almost none of conscientiousness items describe affects. Only for items about agreeableness the three categories are represented almost equally.
What does that mean for the idea about the Big Five being “biologically based basic tendencies”? The results cast serious doubt on that idea. If the basic tendencies idea was right, one would assume that all of the Big Five factors correspond to affects, behaviors or behavioral tendencies, and cognitions equally. The result that some factors have more to do with affects (i.e. neuroticism, and to some extent extraversion), others are mainly about cognitions (openness) and a third category has to do with behavior (conscientiousness and extraversion) is much more compatible with the idea that the Big Five are about different things and not operating at the same level, i.e. that they are not (all) basic tendencies. If one thinks of a “basic tendency” as something in the brain, say, somebody with a higher level of neuroticism being more excitable in some neural network; how might this “basic tendency” be comparable to a “basic tendency” like conscientiousness that seems to be mainly about behaviors? In the words of Pytlik Zillig et al.:
Assume for the moment that there is some very basic core or reality to Big 5–level traits, that the ABC [affect, behavior, and cognition] dimensions are highly meaningful constructs for assessing that core, and that the operational definitions of traits on ABC dimensions in major inventories reasonably reflect those underlying latent traits. Given those assumptions, our findings suggest that abstract arguments (and conceptual definitions of traits, such as found in personality texts) about the basic nature of traits may miss the mark.
As a final remark: this study again shows that words are not equal to their meanings in personality psychology. The Costa and McCrae theorists claim that their Big Five are basic tendencies, biologically based and causally operating. But their instruments do not support this claim. The content analysis of the instruments reveal that the Big Five are different with regard to what they refer to.
¹ I realize that most of the links require subscriptions, but I can’t help citing peer reviewed sources.