What Is the Relationship between Latitude and Brain Size?

Researchers from Oxford University have found that there is a direct correlation between latitude and brain size. People in northern countries have bigger skulls and bigger brains than those in southern countries. This doesn't mean that they are smarter, but rather, that they need bigger vision areas in the brain to deal with the dimmer lighting. The correlation is very specific — in the Oxford study, which included 55 skulls, each skull could be matched to the latitude of the country where the owner lived by its size alone.

More facts about brain size:

• The animal with the largest brain is a sperm whale, with the average sperm whale brain weighing 17 pounds (about 7.7 kg). The smallest mammalian brain is that of the mouse lemur, which weighs about 0.004 pounds (about 2 grams).


• Shrews have one of the largest brains for their body sizes. Some species of shrew hold up to 10 percent of their body weight in their brains.


• If all of a human brain's wrinkles were unfolded, it would be about the size of a pillowcase.