Social behaviors can be categories into four types from an evolutionary perspective. Mutual (+/+), Selfishness (+/-), Altruism (-/+) and Spite (-/-).

In an original, well researched and organized essay (of appropriate academic level: 3000 level University) demonstrate your understanding of evolution by natural selection by making an argument for the natural selection pressures for each of these behaviors. Obviously, one must define/describe the behaviors before one can demonstrate their selection for/against. Examples of each behavior is expected.