1. Chapter 10: Cooperation Cooperation Defined Cooperative Behaviors
Paths to Cooperation
Coalitions
Phylogenies

2. FIGURE 10. 1. Elephant cooperation
FIGURE Elephant cooperation. A multiview perspective of the apparatus and the elephants. The inset shows the setup from above. (Adapted from Plotnik et. al., 2011)

3. Range of Cooperation: Birthing in Bats
FIGURE Bat midwives. Nonpregnant female helpers sometimes tutor pregnant females in the birthing process. The three stages of the process are shown here (A–C). (Based on Kunz et al., 1994)

4. Range of Cooperation: Social Grooming in Primates
FIGURE Primate grooming. Primates of many species engage in various forms of grooming behavior. Such behavior may serve numerous functions simultaneously. (Photo credit: Chris Crowley/ Visuals Unlimited)

5. Paths to Cooperation
FIGURE Four paths to cooperation. Reciprocity, byproduct mutualism, kin selection, and group selection can all lead to cooperative behavior.

6. Reciprocal Altruism
TABLE The prisoner’s dilemma game.

7. Evolutionarily Stable Strategies: TFT
FIGURE Tit for tat. The tit-for-tat strategy has three fundamental characteristics. The individual using TFT is (1) nice—it never cheats first; (2) retaliatory—it always responds to a partner that is cheating by cheating itself; and (3) forgiving—it only remembers one move back in time, and hence is capable of “forgiving” cheating that is done early in a sequence.

8. FIGURE 10. 6. Risk taking and cooperation in guppies
FIGURE Risk taking and cooperation in guppies. Two male guppies (lower left and lower center of photo) inspect a pike cichlid predator. Guppies cooperate during such risky endeavors. (Photo credit: Michael Alfieri)

9. TABLE 10.2. The payoffs for predator inspection.

10. FIGURE 10. 7. The risk of inspecting predators
FIGURE The risk of inspecting predators. Ten groups of six guppies each—two low inspectors, two medium inspectors, and two high inspectors—were placed with a predator in a pool that was one meter in diameter. The probability of surviving thirty-six hours was a function of inspection tendencies, with those inspecting most often suffering the highest mortality. (From Dugatkin, 1992b)

11. FIGURE 10. 8. Information transfer in minnows
FIGURE Information transfer in minnows. Information obtained by inspectors is somehow transferred to individuals that do not inspect. (Based on Magurran and Higham, 1988, p. 157)

12. FIGURE 10. 9. Inspection behavior in the wild
FIGURE Inspection behavior in the wild. A model predator was placed into a tributary of a river in Trinidad, and predator inspection behavior of guppies was recorded. Inspectors recognize the head region of a predator as most dangerous. (A) There were fewer inspections of the predator’s head than of its trunk and tail. (B) Inspector group was smallest when inspecting the head region of a predator. (C) Approach distance was a function of the part of the predator’s body that was being inspected; inspectors stayed farthest away when they were inspecting the predator’s head. (Based on Dugatkin and Godin, 1992)

13. FIGURE 10. 10. “Retaliation” in guppies
FIGURE “Retaliation” in guppies? Pairs of guppies were given the opportunity to inspect a predator. Lead fish in a given section of an aquarium were more likely to turn back and swim to safety than were trailing fish in the same section of the aquarium. This might be interpreted as lead fish “retaliating” against trailing fish, who fail to stay by their side. (Based on Dugatkin, 1991, p. 130)

14. FIGURE 10. 11. Blood-sucking reciprocators
FIGURE Blood-sucking reciprocators. To survive, female vampire bats need frequent blood meals. Individuals often regurgitate part of their blood meals to others, but they are much more likely to do so for those that have shared a meal with them in the past. (Photo credit: Jerry Wilkinson)

15. FIGURE 10. 12. Vampire bat cooperation
FIGURE Vampire bat cooperation. If a hungry bat approaches a satiated bat, she is much more likely to get a regurgitated blood meal if she has fed the satiated bat in the past.

16. FIGURE 10. 13. Vampire bat blood meals
FIGURE Vampire bat blood meals. Wilkinson used twenty-one regurgitation events not involving mothers and their offspring to examine the role of relatedness and reciprocity in sharing blood meals. Bats were much more likely to regurgitate a meal to close kin and to those with which they associated more often. Follow-up laboratory work found that bats were capable of keeping track of those that fed them in the past and those that didn’t. (From Wilkinson, 1984)

17. TABLE 10.3. The monetary prisoner’s dilemma game.

18. FIGURE 10. 14a. The prisoner’s dilemma game and social cooperation
FIGURE 10.14a. The prisoner’s dilemma game and social cooperation. To study the neurobiological basis of reciprocal altruism and cooperation, researchers had subjects play an iterated prisoner’s dilemma game. (A) One of the subjects played from inside an fMRI machine that monitored her brain activity as she played, while the other subject played the game on a computer in a different room. Each subject saw the payoff matrix that represented her own payoffs. (B) The fMRI scans showed that, when both subjects cooperated, brain areas associated with reward processing—the ventromedial/orbitofrontal cortex (OFC), the rostral anterior cingulate cortex (rACC), the anteroventral striatum (including the caudate nucleus and the nucleus accumbens), and the subgenual anterior cingulate cortex (ACC)—were activated. (Based on Rilling et al., 2002; photo credit: James Rilling; reprinted by permission of Cell Press)

19. FIGURE 10. 14b. The prisoner’s dilemma game and social cooperation
FIGURE 10.14b. The prisoner’s dilemma game and social cooperation. To study the neurobiological basis of reciprocal altruism and cooperation, researchers had subjects play an iterated prisoner’s dilemma game. (A) One of the subjects played from inside an fMRI machine that monitored her brain activity as she played, while the other subject played the game on a computer in a different room. Each subject saw the payoff matrix that represented her own payoffs. (B) The fMRI scans showed that, when both subjects cooperated, brain areas associated with reward processing—the ventromedial/orbitofrontal cortex (OFC), the rostral anterior cingulate cortex (rACC), the anteroventral striatum (including the caudate nucleus and the nucleus accumbens), and the subgenual anterior cingulate cortex (ACC)—were activated. (Based on Rilling et al., 2002; photo credit: James Rilling; reprinted by permission of Cell Press)

20. FIGURE 10. 15. The trust game and punishment
FIGURE The trust game and punishment. Two subjects played the trust game while one of them (player A) was hooked up to a PET scanner that monitored his brain activity. The caudate nucleus, which is part of the dorsal striatum of the brain—depicted in yellow—was very active when player A punished player B for failing to return some of the money that A had provided to B. (From de Quervain et al., 2004; reprinted by permission of the AAAS)

21. FIGURE 10. 16. Oxytocin and trust
FIGURE Oxytocin and trust. The level of oxytocin was higher when subjects believed money was sent to them voluntarily (versus sent as a function of a random draw). (From Zak et al., 2005)

22. Path 2: Byproduct Mutualism
FIGURE 10.17a. Harsh environments favor cooperation. (A) A group of yuhinas (Yuhina brunneiceps). (B) During the breeding season, females cooperate with one another more in harsh than in mild environments. (Photo credit: Shen, S., et al Nature Communication; adapted from Shen et al., 2011)

23. FIGURE 10. 17b. Harsh environments favor cooperation
FIGURE 10.17b. Harsh environments favor cooperation. (A) A group of yuhinas (Yuhina brunneiceps). (B) During the breeding season, females cooperate with one another more in harsh than in mild environments. (Photo credit: Shen, S., et al Nature Communication; adapted from Shen et al., 2011)

24. FIGURE 10. 17b. Harsh environments favor cooperation
FIGURE 10.17b. Harsh environments favor cooperation. (A) A group of yuhinas (Yuhina brunneiceps). (B) During the breeding season, females cooperate with one another more in harsh than in mild environments. (Photo credit: Shen, S., et al Nature Communication; adapted from Shen et al., 2011)

25. TABLE 10.4. The P matrix and the M matrix.

26. FIGURE 10. 18. Byproduct mutualism and blue jays
FIGURE Byproduct mutualism and blue jays. Blue jays were tested in a three-stage experiment: stage 1 = prisoner’s dilemma, stage 2 = byproduct mutualism, and stage 3 = prisoner’s dilemma. Jays cooperated when the payoff matrix matched byproduct mutualism, but not when it matched the prisoner’s dilemma. (Based on Clements and Stephens, 1995)

27. FIGURE 10. 19. Food size and food calls in sparrows
FIGURE Food size and food calls in sparrows. (A) The first bird to arrive at a food patch (labeled the pioneer) were more likely to give “chirrup calls” that attracted other birds when resources were more divisible. (B) Pioneers also called more often when food was easily divisible. (Based on Elgar, 1986, p. 171)

28. Path 3: Group Selection
TABLE Cooperating co-foundresses.

29. FIGURE 10. 20. From cooperation to aggression
FIGURE From cooperation to aggression. Queen-queen aggression and queen death rate rise as colonies move to the stage of colony development at which workers emerge from pupae and then begin helping. (From Rissing and Pollock, 1987)

30. FIGURE 10. 21. Extreme cooperation by foraging queen
FIGURE Extreme cooperation by foraging queen. In the ant Acromyrmex versicolor, a single queen (shown in the blowup circle) is the forager for a nest. Such foraging is very dangerous, but all food collected is shared among (unrelated) queens.

31. TABLE 10.6. Harmony among Acromyrmex versicolor queens.

32. Coalitions and Alliances
FIGURE 10.22a. Coalitions. (A) Three male dolphins swim together, forming a long-term coalition (or alliance). Such male coalitions “herd” females. A female is seen to the left of the three males. Occasionally different alliances join together to form superalliances that compete against other such superalliances. (B) Pairs of male chimps often form coalitions to act against larger, more dominant, individuals. (Photo credits: Richard Connor; Frans de Waal)

33. FIGURE 10.22b. Coalitions. (A) Three male dolphins swim together, forming a long-term coalition (or alliance). Such male coalitions “herd” females. A female is seen to the left of the three males. Occasionally different alliances join together to form superalliances that compete against other such superalliances. (B) Pairs of male chimps often form coalitions to act against larger, more dominant, individuals. (Photo credits: Richard Connor; Frans de Waal)

34. FIGURE 10. 24. Baboon coalitions
FIGURE Baboon coalitions. A male baboon (middle) involved in an aggressive interaction (with male on left) will often solicit others to aid him by turning his head in the direction of a potential coalition partner (male on right).

35. The Tragedy of the Commons
FIGURE The tragedy of the commons in grazing animals. Harden illustrated the tragedy of the commons by focusing on the decisions that people had to make about how often they should allow their herd animals (here angora sheep) to feed on a “commons” pasture that is shared by all in the community. (Photo credit: A.N.T. Photo Library/NHPA)