Paris

MAMMALS with large brains tend to be smarter but they also face a greater chance today of going extinct, according to a study published on Wednesday.

Scientists have long known that having oodles of grey matter comes at a certain cost. Supplying a big brain with blood, for example, requires a lot of energy. But even if there isn't a direct correlation between size and intelligence - humans don't have the biggest brains in the animal kingdom, even in proportion to their body size - a bigger bundle of neurons is usually seen as a plus.