Each trial was initiated by the actor pressing a green button on the middle bottom of screen. The actor made a choice by touching one of the three options presented on the screen. A food reward (an apple piece, approximately 1 cm^3^) was given according to the assignments of the options and their functions. The three options consisted in rewarding only the actor (selfish (S)), both participants (prosocial (P)) or only the recipient (altruistic (A)). Feeder activation was accompanied by two distinctive buzzer sounds with slight temporal delay to indicate clearly which feeder was giving the reward. Throughout the procedure the recipient sat in front of a grey screen. After the completion of the experiment (by the end of the third session) the chimpanzees changed positions: the actorBligh is of course most famous as the commander of the Bounty. On returning to London after being cast adrift by the mutineers he ensured that those captured received full naval justice and undaunted by his experiences continued his naval career, reaching the rank of Admiral and becoming Governor of New South Wales in Australia.