Trivers chapter 3

Question 1

Four kinds of social acts

Answer 1

Altruistic, selfish, cooperative, spiteful

Question 2

Altruistic

Answer 2

Actor confers a benefit but suffers a cost

3 types: kinship, return effects, and parasitism

Question 3

Selfish

Answer 3

Actor gains while inflicting a cost

Natural selection favors selfish acts

Question 4

Cooperative

Answer 4

Both parties gain

Question 5

Spiteful

Answer 5

Both parties suffer

Question 6

Kinship

Answer 6

Br > C

For natural selection to favor altruism toward someone related to you, benefit needs to be greater than cost

you and your half-sibling are r = ¼, so benefit must be greater than 4x the cost

Question 7

Return effects

Answer 7

When the act introduces a return benefit to the actor larger than the initial cost

Question 8

Social parasitism

Answer 8

The recipient induces altruism that may not have previously existed
At its core, it is selfish behavior

Question 9

Inclusive Fitness

Answer 9

Includes both an individual’s reproductive success and effects on the reproductive success of relatives

Natural selection favors traits of the individual that maximizes her inclusive fitness

Question 10

Cooperative traits

Answer 10

Two individuals subject to a series of costs and benefits over time

Costs inflicted on both parties