Chunk #40 — Results — Question 3: Can the Relationship Between Behavioral Disinhibition and Response Inhibition Be Explained by Shared Genetic Factors?
Having established that behavioral disinhibition is selectively related to response inhibition, we turned to examining the etiology of this relationship. To do so, we estimated genetic models that included both the behavioral disinhibition and response inhibition latent variables. As shown in Figure 1, the three component measures of response inhibition each make a significant contribution to the latent construct. Individual differences in response inhibition are due almost entirely to genetic influences (a2 = ~.99; note that because the parameters for the two-factor hierarchical model were estimated simultaneously by maximum likelihood, there were minor differences in the inhibiting part of the model at age 12 and age 17). Results provided no evidence of shared environmental influences on response inhibition.
