It should be noted that there is no contradiction between the concept of liability as a single unidimensional trait and that this trait is complex, i.e., contributed to by many diverse influences. In fact, these are common features of complex (multifactorial) traits, such as stature (observed trait) or IQ (index of the latent trait of intelligence). Normal distributions of these traits in the population result exactly from the fact that they are influenced by multiple variables, in accordance with the central limit theorem. Unidimensionality of the trait refers to the structure of covariation between these variables rather than to the total number of the manifold influences potentially determining the shared variance, or to the presence of a single causal influence. The number of such influences for CLA may be substantial. To a considerable degree, they appear to pertain to an identifiable circumscribed group of mechanisms underlying behavior regulation and socialization.
