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
Principle of double effect in dying, etc.), a principle of "double effect death" could be applied to justify the deliberate administration of a pain-killer in potentially unsafe doses—not in an attempt to end life but the pain suffered is considered harmful to the patient. The U.S. Supreme Court has voiced support for this principle in its deliberations over the constitutionality of medical aid in dying. Consequentialists, in particular, reject the notion that two acts can differ in their moral permissibility if both have exactly the same consequences, or expected consequences. John Stuart Mill, a nineteenth-century advocate of the utilitarian version of consequentialism, argues that