so on—as well as acknowledging the operation of dynamic processes
(such as learning, defense, and long-range planning) that directly gen -
erate the flow of experience and behavior. It makes clear statements
about how the environment can and cannot affect traits. One could ar -
gue that it is very sketchy—there is no catalog of dynamic processes, no
theory of identify formation, no principles of psychotherapy to remedycharacteristic maladaptations. But the theory is young, and these detailscan always be filled in later if the basic framework is sound.
But all this probably is not enough to convince most psychologists
of the theory’s merits. T wo objections in particular are likely to beraised: First, the theory does not account for the very traits with whichit is centrally concerned. Second, it does not yield novel predictions bywhich it can be tested. Both of these issues require consideration.
The Structure Postulate asserts that specific personality traits are
organized in terms of the five factors of the FFM. Why , you might wellask, are there five factors and not six or seven? And why these factorsand not others? It would certainly be possible to create theories. For ex-ample, we might try to tie the factors to five distinct regions in thebrain, or we might postulate that each solves a particular adaptive prob-lem that led to its evolutionary development. At some point, we mightexpand FFT to include such postulates.
For the present, however, our view is that the existence of these
five factors is simply an empirical fact, like the fact that there are sevencontinents on the earth (McCrae & John, 1992). If you asked geologistswhy there are just seven continents, and not five or ten, they wouldprobably say that, at this point in the history of the earth’s crust, this ishow things have turned out. Millions of years ago there was one conti -
nent, Pangaea, that broke apart and, as it happened, we now have seven
pieces. Similarly , we would say that in the history of the evolution of thehuman species (or perhaps the evolution of Primates), the brain grewand developed in such a way as to give rise to the FFM.
This is a crucial point in evaluating FFT. If we had derived the
Structure Postulate from a hypothetical mechanism of brain activity orprinciple of social relations and then conducted studies showing that
traits really do covary to define the five factors, we would take it as sup -
port for our theory—probably as dramatic as the early confirmations of
Albert Einstein’s prediction that light would bend around massive bod -
ies. But clearly the existing literature is not proof of the Structure Postu -
late: It is the basis of the postulate. Almost all theories begin withA Five-Factor Theory of Personality 201