Beard vs. forehead, ten years later.
Ten years ago (1988), we observed in a sample of 100 men that the area of the glabrous skin above the eyebrows was proportional to the area of the hairy skin on the cheeks, lips, and chin. Ten to 11 years later, we measured again 39 of the former subjects to check longitudinally whether the relationship would still be valid. In the group of 39 subjects, the correlation was again significant and the regression was practically the same as that obtained in the same sample 10 years earlier. This would tend to show that ontogeny follows phylogeny. This results is understood as indirect evidence in favor of selective brain cooling in humans. Am. J. Hum. Biol. 12:460-464, 2000. Copyright 2000 Wiley-Liss, Inc.
Journal Article↗