“ Imagine two animals, otherwise identical, where only one is predisposed to care for its children in a way that increases their chances of survival. Whatever heritable properties cause this animal to be a caring parent will spread through the population, because the offspring of that animal will have a greater chance of surviving…”
What about cases that can’t be explained in terms of genes or relatedness?
So what do we do with altruism?
Darwin The Descent of Man (1871) “ The following proposition seems to me in a high degree probable – namely, that any animal whatever, endowed with well-marked social instincts, would inevitably acquire a moral sense or conscience, as soon as its intellectual powers had become well developed, or nearly as well developed, as in man” (chapter III, p71) “ Thus the social instincts, which must have been acquired by man in a very rude state, and probably even by his early ape-like progenitors, still give the impulse to many of his best actions” (chapter III, p86)
The Prisoner’s Dilemma was one of the earliest “games” developed in game theory. By simulating the Prisoner’s Dilemma we are given an excellent method of studying the issues of conflict vs. cooperation between individuals.
Since the Prisoner’s Dilemma is so basic, it can be used as a model for various schools of thought, from economics to military strategy to zoology, and even Artificial Intelligence.
These inequalities rank the payoffs for cooperating and defecting.
The condition of R > (T+S)/2 is important if the game is to be repeated. It ensures that individuals are better off cooperating with each other than they would be by taking turns defecting on each other.
Single instance games of PD have a “rational” decision. Always defect, since defecting is a dominating strategy. However, with iterative PD always defecting is not optimal since an “irrational” choice of mutual cooperation will cause a net gain for both players. This leads to the “Problem of Suboptimization”
Bonobos are different from other apes in that they are more peaceful. Females hide estrus=no competition for mates. Engage in frequent sexual activities. Females dominate and attempt to keep peace.
Strong female alliances formed. They work together to diffuse tension in the group.
Aggressive behavior is only one of several ways in which conflicts of interest can be settled. Other possible ways are tolerance (e.g., sharing of resources), or avoidance of confrontation (e.g., by subordinates to dominants).
Both chimps and bonobos rely on development of coalitions and community acceptance – even chimps will ostracize a violent bully which means they must survive on the edge of other groups territory – definitely will be severely attacked
A fundamental difference between chimpanzees and bonobos: chimpanzees “resolve sexual issues with power while (bonobos) resolves power issues with sex”
Frans De Waal
Weaning A weaning compromise has been arrived at between a mother chimpanzee and her 4-year-old son. After repeated nursing conflicts, the son is permitted to suck on a part of the mother's body other than the nipple.
Male bonobos are alert to opportunities to ascend power positions in social hierarchy
Must be patient as upward mobility depends on mothers position
Forms partnerships (coalition) to support position usually with brothers or close friends
Often inherit power from a powerful mother
Frans De Waal
Reconciliation Other evidence of an evolved moral sense can be seen in what happens after a conflict occurs. The nature of the social relationship determines whether repair attempts will be made, or not.
If there is a strong mutual interest in maintenance of the relationship, reconciliation is most likely. Parties negotiate the terms of their relationship by going through cycles of conflict and reconciliation.
Kiss to make-up Fig. 2. Chimpanzees typically seal a postconflict reunion, or reconciliation, with a mouth-to-mouth kiss, as here by a female (right) to the dominant male. De Waal, F. B. M. (2000). Primates--a natural heritage of conflict resolution. Science, 289 (5479), 586-590.
Most primates show a dramatic increase in body contact between former opponents during post conflict (PC) as compared with matched-control (MC) observations The cumulative percentage of opponent-pairs seeking friendly contact during a 10-min time window after 670 spontaneous aggressive incidents in a zoo group of stumptail macaques
Reconciliations allow rhesus monkeys to maintain tight kinship bonds despite frequent intrafamilial squabbles. Shortly after two adult sisters bit each other, they reunite sitting on the left and right of their mother, the alpha female of the troop, each female holding her own infant. The sisters smack their lips while the matriarch loudly grunts.
Capuchin fairness study: Brosnan, S., and F. B. M. de Waal. 2003. Monkeys reject unequal pay. Nature 425:297-299.
Brosnan performed a lab experiment in which capuchin monkeys are given a small token (a rock) that they can then return to the experimenter in exchange for a food reward. They like cucumbers alright, but grapes are the really preferred reward. Two capuchins were situated side-by-side in visible but not physical contact of each other, both were presented with an exchange opportunity in turn, and the second monkey’s reaction was the focus of the experiment. Separately both individuals had very high rates of successful exchange.
monkey A exchanges token for a cucumber, then subject monkey B also exchanges for a cucumber
- monkey A exchanges the token for a wonderful grape, but then subject monkey B is given only a cucumber in exchange
- monkey A gets a wonderful grape for “free” without an exchange, but subject monkey B then has to go through with the exchange for only a cucumber
This is suggested to perhaps be a sense of “fairness” or “justice”. Males didn’t seem to care either way, but female subjects tended to refuse the inequality cucumber exchange – they either refused to take the cucumber or they took it and then quickly threw it back at the experimenter. Thus they conclude that capuchin females pay more attention to the value of exchanged goods and services and are willing to sacrifice a small gain when their neighbor gets a greater reward. Is this due to spite?
A sense of “fairness” but also tolerance for inequality for close friends
Plenty of evidence from chimpanzees and bonobos to humans showing that many of our moral instincts have been around a long time, all primates demonstrate: See: de Waal (1996) Good Natured, and Flack & de Waal. 2000. 'Any animal whatever'