London, Oct 11 (IANS) Are you docile or aggressive? Well, that depends on your personality type, says a new research.

"Some of us are couch potatoes while others are drawn to sport and exercise," notes Peter Biro, senior lecturer at the University of New South Wales.

"We often associate the athletic 'jock' type of person with being aggressive and social, whereas the more sedentary 'nerd' is often seen as more socially awkward and submissive," said Biro.

His review study concludes that there is now enough evidence to suggest a link between a personality type and the rate of its metabolism - the process that converts food into the energy that fuels the body, reports the journal Trends in Ecology and Evolution.

"Mice spend considerable time on running wheels, for example, and other animals often pace back and forth in zoo enclosures. Given they don't need to move about in search of food as they would in nature, we might ask why they are apparently 'exercising'."

Recent research suggests that this behaviour might be related to an individual's metabolic capacity, said a New South Wales release.

For example, mice in isolation that have high metabolism tend to spend more time on running wheels, and run faster, than those with low metabolism.

Male crickets with sex on their mind tend to call to attract mates more and have higher metabolism than those with slower metabolism.

Metabolism and aggression are also linked. It has now been documented, for example, in several species of fish and birds that individuals with high metabolism tend to be more aggressive and dominant over those with slow metabolism.