If a credit card company does not loan money it does not gain from loaning. While a delinquent debtor does get a short term payoff, the bad credit rating makes it impossible to get money in the future. Thus, the debtor pays of debts and the credit card company takes in interest. We will look at the familiar Neighbor Tit for Tat in territorial birds. The evolution of tit for tat is contingent on a number of other behaviors such as individual recognition of partner in the cooperation.
Many animals show interesting cooperations when dealing with predators.
Predator inspection behaviors could reflect a tit for tit. An alternative for such behaviors is the selfish herd hypothesis which we will also explore. Finally, simultaneous hermaphrodites and reciprocal fertilization presents a unique example of tit for tat, in which the fitness costs and benefits of cooperation are tightly related to fitness. This would be the retaliator move. Two fish swim side by side.