The "winter born phenomenon" among schizophrenics: differences between blacks and whites.

Reviewed the literature on birth seasonality among schizophrenics and reported data on highly significant differences between the quarterly birth patterns of black and white schizophrenics (N = 724). The findings strongly indicate that specific subgroups of schizophrenics are especially likely to be winter-borns. Log-linear analyses uncovered a highly significant difference between the birth seasons of black and white patients. Black schizophrenics are especially likely to be winter-borns, while white schizophrenics had a birth peak in the fall. We speculate about the causes of this race-specific finding from a perspective that is sociological and neurophysiological.