People living in the northern hemisphere have bigger brains than those staying near the equator, says a study.

Unfortunately, that doesn't necessarily mean northerners are more intelligent than people from the south — just that they have evolved to cope with the longer winters and greyer skies in northern climes, say British researchers.

In fact, a team at Oxford University, who measured the brain volume of 55 skulls from around the world, came out with this intriguing theory that people from countries further from the equator have more grey matter and larger eyes than those from sunnier parts, The Daily Telegraph reported.

This is because living in low light conditions means the eyes and brain need to work harder in order to process images to a good level of detail, or “high resolution”, say the researchers.

Lead author Eiluned Pearce said the study suggests that the bigger brains and eyes are needed to see properly in dimmer light.

“As you move away from equator, there's less light available, so humans have had to evolve bigger and bigger eyes. Their brains also need to be bigger to deal with the extra visual input. Having bigger brains doesn't mean that they are smarter, it just means they need bigger brains to see well where they live,” she said.

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