Rejecting the null confirms the substantive. Factor analysis reverses this logic by interpreting acceptance of the null as confirmation of the substantive hypothesis. Trying out items with selection and discard based on item correlations is a major part of the standardised test construction enterprise. Tests are intended to sample performance in some aspect of the test taker's environment. Evolution occurs because individuals with different characteristics perform differently in different environments.
Natural selection reflects an advantage for a particular characteristic in a particular environment.
For genetic characteristics then, the necessary condition for natural selection is the existence of such genetic-environmental interactions. Thus, from a genetics perspective, a test item samples the performance of an individual in some niche of her world. Accordingly, if performance has any hereditary component then one expects genetic-environmental interactions. In theory, it is possible that some performances have no such interactions, but those of us who work with infrahumans would be hard put to identify a characteristic that has not been found susceptible to some degree of selective breeding. This has been verified experimentally.