The relationship is demonstrated between two explanations for the attenuation of observed trait-behavior and behavior-behavior correlations: multiple determinacy, as explicated recently by Ahadi and Diener and by Strube, and measurement error, as discussed previously be Epstein, Ajzen, and others. The former pertains to multiple determinants of a behavior construct other than the trait of interest, whereas the latter pertains to multiple determinants of a behavior measure other than the behavior construct of interest. However, it is shown that in the two cases the fundamental psychometric principles involved are the same. Implications of this integrated conceptual perspective are explored with respect to the magnitude of observed trait-behavior and behavior-behavior correlations that should be expected under different circumstances, focusing particularly on the distinction between global and more narrowly defined traits.