For example, when the researchers asked Musa Abu Marzouk, deputy chairman of Hamas, about a trade-off for peace without granting a right of return, he said “No.” When he was offered a trade-off with a substantial material incentive, he said “No” even more emphatically; “we do not sell ourselves for any amount.” But when he was offered an apology, he said “Yes,” although an apology would only be a beginning. “Our houses and land were taken away from us and something has to be done about that.”