To allow an adequate evaluation of my theory, I (a) tabulate previous data showing that, on average, Mongoloids are greater than Caucasoids are greater than Negroids in brain size and intelligence, maturational delay, sexual restraint, quiescent temperament, and social organization; (b) analyze new data demonstrating that race differences in crime occur internationally; (c) discuss the predictive power of race for behavior; (d) show the existence of enduring traits of character; (e) show Lombroso to have been correct in some of his beliefs about the biological basis of crime; (f) review evidence suggesting that the race differences in crime have a genetic basis; and (g) propose that future research investigate the neurohormonal basis of crime. Figure, 4 tables, 50 references. (Author abstract)