Mammals having larger brains in relation to size of body tend to have longer lives.

This newest discovery is based on a study of around 500 mammal species by the Centre for Ecological Research and Forestry Applications (CREAF), affiliated to Universitat Autònoma de Barcelona.

The size of brain of some mammals including chimps, gorillas, whales, dolphins and elephants are larger than expected for their body size.

Researchers spent years investigating why nature favours the growth of large brains given that they need much more time to attain functional maturity and they make use of so much energy.

One of the classical clarifications is the theory of Cognitive Buffer Hypothesis (CBH).

It suggests that a larger brain provides more flexibility in behavior when confronting environmental changes and makes learning simple.

CREAF researchers César González-Lagos and Daniel Sol, along with Simon Reader of University McGill, Canada, carried out the study.

Utilizing statistical techniques, the study authors examined data from 493 mammal species - from rodents and bats to cetaceans, felines, ungulates and marsupials and concluded that having a larger brain entails having a longer life.