How Does the Shape of a Head Affect the Brain?

Q: Did cranial deformation as practiced by the ancient Mayans change or impair brain function?

A: The famous slanted forehead that was apparently a mark of high rank among pre-Columbian Mayans was achieved by various forms of compression of the head in infancy. It is believed by many researchers to have had no significant effect on cranial capacity and how the brain worked, the conclusion of a 1989 study of skulls in The American Journal of Physical Anthropology.

But there is no direct evidence to support this contention, no large study comparing brain development in living populations that do and do not practice head flattening. An extensive review article in the journal Anthropology in 2003 speculated that the practice of compression had the potential to damage the delicate developing frontal lobe, as is seen in certain conditions.

The authors speculated that such damage could have impaired vision, object recognition, hearing ability, memory, attentiveness and concentration. These factors in turn might have contributed to behavior disorders and difficulty in learning new information.

Still other researchers suggest that the diverging conclusions can be attributed to how the skull measurements are done. The compression may have affected the shape of the face more than the brain itself, they said.