In a study involving 140 three year olds divided into 70 pairs of boys or girls but not mixed groups, children of each group were asked to perform a task to win a prize. Each group faced one of three situations that made completing the task impossible. In the first case a tool necessary to perform the task of one of the two children of a pair (never both) broke. In the second case, unknown to the children, a tool used by one of the two children was much harder to use than that of the other child of that pair. In the third case one of the two children of a pair was secretly told that when he/she heard a bell ring he/she had to abandon the collaboration with his/her companion and go and play on his/her own. In the first case (called force majeure) most couples tried to mend the instrument together so initiating a new collaboration. In the second case (where it appeared that one of the two children was incapable of performing the task) most children whose tool was not defective tried to help the companion who seemed helpless. In the third case (where one of the two children appeared to be very selfish) the other member of the pair protested vehemently. This study shows that three year olds are capable of collaborating and know what it means to make a commitment.