New York, Nov 27 (IANS): Devastating though they are, wars have taught humans to collaborate with people they are not related to and solve problems requiring high intelligence, finds new research.

Humans are a unique species where collaboration is widespread and not limited to relatives, the researchers pointed out.

Collaborative ability evolves easiest if there is direct conflict or warfare between groups, explained lead author Sergey Gavrilets, professor at the University of Tennessee.

"Our ability to effectively collaborate with others is largely responsible for what our species came to be," Gavrilets pointed out

Intelligence and cooperative behaviour can co-evolve to solve the problem of collective action in groups and to overcome the costs of having a large brain, the findings showed.

The researchers developed a mathematical model to solve the evolutionary puzzles of how humans developed high intelligence and collaboration despite the various costs of having a big brain.

The model challenges influential theories on when large-game hunting and within-group coalitions first appeared in humans.

Some scientists say that within-group coalitions and collaborative hunting came first and then subsequently created conditions for the evolution of collaboration in between-group conflicts.

Yet, Gavrilets' model showed the opposite: that collaboration in between-group fighting preceded both within-group coalitions and collaborative hunting.

The study appeared in the Journal of Royal Society Interface.