Instead, the extra grey matter simply helps them see clearly in the lower light levels that come with living at high latitudes.
To put it another way, Northern dimness led to the evolution of bigger brains.
The intriguing theory comes from Oxford University scientists who measured the brain volume of 55 skulls from around the world.
Some were English, others came from as far afield as China, Africa and the Pacific Islands.
Plotting brain volume with the geographical location of the personâ€™s country clearly showed that the further north they lived, the bigger their brain.
Scandinavians had the most brain power and Pacific Islanders the least. Measurements of the eye sockets also showed that those from northern climes had bigger eyes.