On

On weaving personality into a tapestry of traits

Cattell set out a set of conditions for how one might ‘distinguish’ among ‘modalities of traits’, which he referred to as ‘dynamic’ ‘temperament’ and ‘abilities’. Cattell made the most fundamental point that analysis of any single behavior will not, in and of itself, allow one to infer the influence of a unique trait, because each behavior varies, to a greater or lesser extent, as a function of all three different trait domains. Cattell argued that by the integration of experimental psychology methods (e.g. by presenting the individuals with a constant task, but different incentives), one could use the associations between different tests and the recently developed tools of factor analysis, to reveal the underlying hypothetical motivational construct factor or factors. Similarly, he argued that one could reveal ability factors by changing the complexity of the test. Finally, he proposed that personality factors could be revealed only by exclusion—these traits could be identified by their resistance to changes in the other two domains (incentives and test complexity).