Because trait psychology is philosophically primitive, personality testers ignore or cannot recognise the problem of circularity of argument which haunts their enterprise. For example, they assume that personality traits are enduring, pervasive and affect all aspects of behaviour.
Since they cannot be observed, personality traits are theoretical constructs which are measured indirectly by self-report inventories. Importantly, personality traits are assumed to be “inner powers” because they allegedly “cause” individuals to act in certain ways. How these theoretical constructs get their power has never been explained. American psychologist David McClelland referred to them, with a smile, as “mental viruses”.
Personality traits, then, are inferences from the behaviour which gave rise to them. “Anxiety” is an inference from behaviour which is called “anxious”. How do we know that individuals are anxious? They are anxious because they behave anxiously. Why do they behave anxiously? They behave anxiously because they are anxious. There is no way of breaking out of this circle of spurious argument unless personality traits and the behaviour they are derived from are separately identifiable. This cannot happen because personality traits are abstractions.Since personality tests have repeatedly failed to predict management performance, one might expect on rational grounds that managers would have by now rejected them. This happened to phrenology a century ago and it should have happened to personality testing a half-century ago.