Evaluation of an evolutionary model of self-preservation and self-destruction.

According to deCatanzaro's mathematical model of self-preservation and self-destruction, staying alive actually may reduce inclusive fitness for an individual who is low in reproductive potential and, at the same time, poses such a burden to close kin that it costs them opportunities for reproduction. Predictions generated from this model were tested using 175 university students as subjects and variables constructed from a 164-item questionnaire. The criterion variables were separate measures of depression, hopelessness, and suicide ideation and behavior. The predictor variables derived from the model were separate measures of reproductive potential of the individual, the individual's perceived benefit or cost to kin, and reproductive potential of the individual's kin. As predicted, there were negative and significant bivariate correlations between each of the model-generated predictor variables and one or more of the criterion variables. Multiple regression analyses showed that benefit to kin was the best predictor of both depression and hopelessness. Discriminant analysis showed that reproductive potential of kin significantly differentiated suicide attempters from nonattempters. Overall, our results support and extend deCatanzaro's model and empirical findings.