Impulse

Why do some of us act more impulsively than others? Cambridge scientists think they may have found the answer - a part of the brain which responds to the lure of a reward for behaviour: and in us all there's a struggle between instant gratification or the hope of a bigger reward later. The Today programme's Jim Naughtie talks to Dr Rudolph Cardinal who has been doing the research and Sally Graham-Moon who indulged in one of the most celebrated pieces of instant gratification in the last decade.