The impulse which told ancient foragers to give up on one pasture and move on to more fertile hunting grounds is the same as that which urges us to try a different internet site if our initial choice is taking too long to appear on screen, the experts believe.

Scientists found that a section of the brain called the dorsal anterior cingulate cortex (ACC) appears to be responsible for weighing up reward against cost in any given situation.

When a certain threshold is reached, the brain gives a signal to throw in the towel.