IT'S official - keeping up with the Joneses isn't small-minded, it actually makes your brain grow.

IT'S official - keeping up with the Joneses isn't small-minded, it actually makes your brain grow.

New research claims it is the main reason why the human brain has tripled in size over the past two million years, since cavemen had to out do each other to survive.

Scientists in the USA, who studied the skulls of our early ancestors, say that while the changing world and climate play a part, competing against others is the biggest factor in brain development.

The research by the University of Missouri looked at the skulls of 153 early human ancestors going back two million years.

Researchers examined the increasing size of the skulls over the centuries.

Taking everything into consideration, the brains which developed the fastest were of those people who lived in bigger populations.

Professor David Geary, leading the study, said: "Our findings suggest brain size increases the most in areas with larger populations and this almost certainly increased the intensity of social competition."