Cooperation is central to human social behavior. Back in the early, dawning days of humanity, we were inferior from nearly every point of view, and cooperation was mainly what brought us to the dominating species status we have today.
But choosing to cooperate with others, while always benefic for the group, often requires individuals to give up a small percent of their own, personal incentive. Rand DG, Greene JD, Nowak MA, from Harvard University, Cambridge and Massachusetts set out to find if people are predisposed towards selfishness, behaving cooperatively only through active self-control or if they are intuitively cooperative, refraining from doing so only after a conscious effort. What they found was truly interesting.
According to their study, which consisted of ten economic games, subjects who reach their decisions more quickly are are more cooperative, and furthermore, forcing subjects to act more quickly makes them more willing to cooperate and share, while on the contrary, forcing them to think for a longer period of time makes them decreases social contributions.
In order to explain and interpret these results, researchers explained that cooperation is intuitive because cooperative heuristics are developed in daily life where cooperation is typically advantageous.