Altruism (biology) most common mechanism of reciprocity in nature, this kind is present in humans, primates, and many other mammals. Also known as, "If you're nice, I'll be nice too." This mechanism of reciprocity is similar to the heuristic of the golden rule, "Treat others how you would like to be treated." Parties mirror one another's attitudes, exchanging favors on the spot. Instant attitudinal reciprocity occurs among monkeys, and people often rely on it with strangers and acquaintances. Also known as, "what have you done for me lately?" Individuals keep track of the benefits they exchange with particular partners, which helps them
Joint wills and mutual wills postponed to take effect only after the death of the second or last testator when the property, or what was left of it, came into the hands of his personal representatives. Another issue as regards mutual wills is the question of revocability. In "Re Hobley" Charles Aldous QC held that there could be either unilateral or mutual revocation provided it occurred during the lifetime of both testators. However, the problem with this approach is that unilateral revocation is against the general principle of contract. Several explanations for this could be proffered. Firstly, there could be an implicit term that the