The reasons why the human beings can be altruistic to non relatives and without the expectation of a reciprocity.
Answers
Explanation:
Reciprocal altruism in humans refers to an individual behavior that gives benefit conditionally upon receiving a returned benefit, which draws on the economic concept – ″gains in trade″.[1] Human reciprocal altruism would include the following behaviors (but is not limited to): helping patients, the wounded, and the others when they are in crisis; sharing food, implement, knowledge.[2]
The concept of ″altruism″ was firstly coined by the French philosopher Auguste Comte in the 19th century, which was derived from the French word ″altruisme″.[3][4] Comte believed that ″altruism″ is a moral doctrine, which is the opposite of egoism, emphasizing the noble morality of sacrificing themselves and benefiting others. Human beings have both selfish and altruistic motivations, and altruism is used to restrain the egoistical instinct.[5] Comte's altruism describes the nature of human and ethical significance, but it's completely different from the altruism in biological sciences. In evolutionary biology, altruism is an individual behavior that benefits another individual's fitness but reduces their own fitness in population.[2][6] The concept of ″altruism″ in biology arose from the debate of ″the Problem of Altruism″ in Natural Selection.[1] Charles Darwin suggested that animals behave in the ways that can increase their survival and reproductive chances while competing with others. However, altruistic behavior – the act of helping others even if it accompanies with a personal cost – is common in the animal kingdom, like the vampire bat[7] and various primates.[8] Therefore, Charles Darwin regarded ″the Problem of Altruism″ as a potential fatal challenge to his concept of natural selection. In ″The Descent of Man″, Darwin (1859)
He who was ready to sacrifice his life, as many a savage has been, rather than betray his comrades, would often leave no offspring to inherit his noble nature.
In 1964, William Hamilton developed mathematical model and put forward to his theory – ″Kin selection″ theory or ″inclusive fitness″ theory reveals that an altruistic gene evolved by natural selection[10]. The gene can be only shared with relatives, and reduces the individuals own fitness but boots the fitness of their relatives and off-springs. In this way, this behavior increases the proportion of altruistic gene in population. Hamilton's rule provides mathematical inequality to state that an altruistic gene spread by natural selection only if the following condition can be satisfied: r B > C, where C is the cost to the individual performing the altruistic act, B is the benefit gained by the recipients of the altruistic act, r is the genetic relatedness between individual and recipients.