All of these skulls would be different. The male and female skulls are easily identifiable, as are the different races. Rich is distinguishable from poor based on dental care for modern skulls or tooth wear in ancient ones (dull flat teeth indicate poverty, because of poorly ground, rock dust contaminated flour, while tooth decay indicates wealth because of access to sugar). Even gay is distinguishable from straight, because gay is associated with extremely high levels of testosterone. And the fed skull glows in the dark.