The final analysis set employed path analysis methods to illuminate and clarify the interactive relationships revealed in analysis set #3 between conduct problems, obesity, and frontal P300a latency. Using Mplus™(51), we constructed and tested two alternative models. The first model hypothesized a causal chain in which the number of conduct problems predicts BMI which, in turn, predicts P300a latency. The second model viewed P300a latency as a phenotypic marker indicating risk for obesity rather than, as in Model #1, a physiological index of the neural damage caused by it. Its causal chain began with frontal P300a latency predicting conduct problems, which then predicts BMI. Conventional measures of model fit, i.e., discrepancy χ2, Root Mean Square Error of Approximation (RMSEA), and Comparative Fit Index (CFI), as well as standardized path coefficients, were computed.
