CHAPTER 9: COOPERATIVE ALLIANCES
Chapter Summary
We started this chapter by considering the problem of altruism: design features that aid the reproduction
of other individuals, even though the altruist who has this feature incurs a cost. The puzzle is how such
altruism could have evolved, given that it seems to go against Hamilton’s rule. One solution came from
the theory of reciprocal altruism, which states that psychological mechanisms for providing benefits to
nonrelatives can
evolve as long as those benefits are reciprocated in the future. The most important adaptive problem the
reciprocal altruist faces, however, is the threat of cheaters—people who take benefits without
reciprocating at a later time.
One solution to this problem emerged from a computer tournament conducted by Robert Axelrod. He
discovered that tit for tat—a strategy of cooperating on the first move but reciprocating thereafter—was
highly successful. It tended to promote cooperation but also helped to solve the problem of cheating by
punishing defectors immediately.
Examples of reciprocal altruism occur in the animal world. Vampire bats share their blood with “friends”
who were unsuccessful on any given night; at a later point, the friends reciprocate the favor, giving blood
preferentially to those who have recently helped them. Among chimpanzees, reciprocal alliances form
among males, among females, and among males and females.
In addition to kin altruism and reciprocal altruism, two other evolutionary theories have been proposed to
explain altruism: indirect reciprocity and costly signaling. With indirect reciprocity, altruists do not
benefit by gaining a return benefit from the person they helped. Rather, others who witness or hear about
their generosity are more likely to provide aid to the altruists. With costly signaling, acts of great helping
and self-sacrifice provide an honest signal to others about one’s condition and resource-holding potential
because
only those in excellent condition can “afford” to provide the costly signal. Costly signaling increases a
person’s status and reputation, which in turn benefits the costly signaler. In sum, there are at least four
ways in which altruism can evolve: kin selection (altruism toward genetic relatives), reciprocal altruism,
indirect reciprocity, and costly signaling.
is to become irreplaceable: If we provide benefits that no one else offers, our friends have a tremendous
stake in our welfare and will therefore want to help when we most need it. A key distinction is between
fair-weather friends and true friends. We tend to know who our true friends are from their behavior
toward us when we most need their help. It is possible that the sense of alienation many people feel stems
from the fact that humans have conquered many “hostile forces of nature,” and so are less likely to face
life-threatening events that allow us to know who our true friends are—those who are deeply engaged in
our welfare.
Some work examines the functions of friendship by exploring the perceived benefits and costs of
friendships. Men and women form same-sex friendships as well as opposite-sex friendships, but the
evidence points to sex differences in the functions of friendship. Men more than women perceive short-
term sexual access as a benefit of opposite-sex friendships. Women more than men perceive protection as
a benefit of opposite-sex friendships. Both sexes perceive information about the opposite sex to be an
important benefit of opposite-sex friendship. One cost of same-sex friendship is the potential for sexual
rivalry. Sexual rivalry appears to be more prevalent among male friends than among female friends,
perhaps because of men’s stronger desire for short-term mating, which would throw them into conflict
more often.
Suggested Readings
Bereczkei, T., Birkas, B., & Kerekes, Z. (2010). Altruism toward strangers in need: Costly signaling in an
industrial society. Evolution and Human Behavior, 31, 95–103.
Cosmides, L., & Tooby, J. (2005). Neurocognitive adaptations designed for social exchange. In D. M.
Buss (Ed.), The handbook of evolutionary psychology (pp. 584–627). New York: Wiley.
DeScioli, P., & Kurzban, R. (2009). The alliance hypothesis for human friendship. PLoS ONE, 4, 1–8.
Multiple Choice Questions
(a) is a greater selective force than the problem of social exchange
(b) does not imply the value of cheater detection in defining the evolution of mechanisms
designed to guide altruistic acts
(c) describes problems associated with how altruism among non-relatives could evolve given the
selfish designs that aid in the reproduction of non-relatives at a cost to the altruist
(d) describes problems associated with how altruism among collateral relatives could evolve
given the selfish designs that aid in the reproduction of more closely related relatives at a cost to
the altruist
(a) a form of cheater detection
(b) a term used to describe the gamut of social relationships
(c) a method designed to determine who is a cheater and who is an altruist
(d) a form of cooperation
(a) defines the conditions under which mechanisms favoring altruism can evolve
(b) states that psychological mechanisms for providing benefits to non-relatives can evolve as
long as the delivery of such benefits is reciprocated at some point in the future
(c) both (a) and (b)
(d) neither (a) nor (b)
(a) The scenario in which each party receives more in future returns than it costs to deliver the
benefit
(b) A benefit given to a provider in exchange for a benefit received earlier
(c) A benefit given to a person in exchange for an assumed repayment in the future
(d) The scenario in which one person receives an immediate benefit
(a) ensuring that the costs incurred could not be used more effectively elsewhere
(b) ensuring that benefits bestowed will be returned in the future
(c) ensuring that benefits bestowed might be returned in the future
(d) ensuring that the costs incurred do not exceed the benefits that may be received in the future
6. The _____________ is a hypothetical situation in which two people are forced to weigh the costs and
(a) temptation to defect
(b) reward for mutual cooperation
(c) sucker’s payoff
(d) Prisoner’s Dilemma
7. If the Prisoner’s Dilemma game is played only once, the best choice of action for a given player would
(a) defect
(b) cooperate
(c) tempt
(d) behave altruistically
(a) the most unlikely strategy to succeed
(b) the Tattle strategy
(c) the simplest strategy devised
(d) the most complex strategy devised
(a) Partners can opt out of the game; each partner knows in advance the strategy of the other.
(b) Partners possess equal power to punish and reward; partners cannot communicate with one
another.
(c) Each partner knows in advance the strategy of the other; partners possess equal power to
punish and reward.
(d) Partners cannot communicate with one another; partners can opt out of the game .
(a) cooperating on the first move, then reciprocating a partner’s move for each move thereafter
(b) defecting immediately
(c) reciprocation on every other move
(d) always cooperating
11. Which of the following is NOT a means of promoting cooperation, as identified by Axelrod? (d)
(a) enlarge the shadow of the future
(b) teach reciprocity
(c) respond quickly to provocation
(d) insist on more than equity
12. Wilkinson discovered that vampire bats __________ regurgitate a portion of the blood they have
(a) do not
(b) non-randomly
(c) selectively
(d) None of the above
(a) aligning themselves with lower-status males
(b) exploiting changes in the structure of female hierarchies
(c) soliciting relationships with females
(d) creating social groups of eight or more
(a) Axelrod
(b) Hamilton
(c) Cosmides and Tooby
(d) Trivers
(a) focuses on problems of reciprocal altruism but has a greater focus on kin relationships
(b) was developed originally with chimpanzees but later applied to humans
(c) was developed to explain cooperative exchange in humans with an emphasis on how humans
have solved the adaptive problem of cheater detection
(d) was developed to explain cooperative exchange in humans with an emphasis on how humans
have solved the adaptive problem of alliance formation
(a) organisms have mechanisms to detect and avoid cheaters
(b) organisms avoid investing heavily in unrelated others
(c) the resident social group consists of 50 to 200 individuals
(d) most members of the population engage in some form of altruism
17. Which of the following was not a cognitive capacity that must have evolved to motivate forming
(a) the ability to recognize many different individuals
(b) the ability to communicate one’s values to others
(c) the ability to model the values of others
(d) the ability to remember all aspects of the histories of interactions with different individuals
(a) exclusive cooperators; exclusive cheaters
(b) opportunistic cheaters; exclusive cooperators
(c) men; women
(d) women; men
19. The Wason selection task and modifications of it suggest that humans are good at ___________ but
(a) detecting cheaters in social exchange, abstract problems
(b) detecting social status, determining the source of others’ social status
(c) estimating reproductive value, estimating mate value
(d) reciprocal altruism, social exchange
20. Individuals in other cultures, such as the Shiwiar, do ____________ Harvard University
(a) much poorer than
(b) much worse than
(c) as well as
(d) slightly better than
(a) one’s social experience
(b) one’s point of view
(c) one’s sex
(d) one’s age
(a) examine the reproductive value of children to determine where investment is most beneficially
spent
(b) assess the genuineness of an altruistic act
(c) assess a cheater’s intentions to reciprocate
(d) assess an altruist’s motives for bestowing benefits
23. Successful performance on cheater detection tasks is _______________ successful performance on
(a) not linked to
(b) greater than
(c) less than
(d) the same as
(a) the ability of all humans to interact with and benefit from others
(b) a diminished capacity to attract altruists through a damaged reputation
(c) a motivation to exploit a partner who is cooperating
(d) an altruistic act towards a complete stranger especially when others are watching
(a) signals to potential social allies that you are a costly partner because you require a greater than
average amount of reciprocation
(b) an incapability of investment because the costs you incur exceed the benefits you are capable
of bestowing
(c) altruism that is not costly but yields a signal to others that he or she is willing to invest
(d) altruism that is costly to the provider and thereby yields honest signals to others regarding
one’s quality as a coalitional ally
26. People report _________ when they help others in need without insisting on, or expecting, any future
(a) feeling pleasure; a sign of friendship
(b) being distrustful; psychological mechanism to deter future social interactions with this person
(c) feeling pleasure; psychological mechanism designed to reward cooperation
(d) feeling pride; psychological mechanism designed to reward cooperation
(a) resources are limited and should be invested judiciously
(b) those who need money the most are least likely to receive money and those that need it the
least are the most likely to receive money
(c) those who need money the most are most likely to receive money and those that need it the
least are the least likely to receive money
(d) those who are less needy are less valuable social allies than those who are more needy
(a) Replaceable; irreplaceable
(b) Irreplaceable; replaceable
(c) Altruistic; a cheater
(d) Young; an elderly person
29. Which of the following group members should feel most threatened by a new male group member
(a) the engineer
(b) the girl next door
(c) the alpha male
(d) the class clown
30. Which of the following is NOT a strategy for increasing the odds of becoming irreplaceable, as
(a) promotion of reputation
(b) cultivate specialized skills
(c) seek out groups that reciprocate the attributes you offer
(d) drive off threatening rivals who offer what you formerly did
31. Tooby and Cosmides argue that selection should fashion assessment mechanisms that make
(a) concern over welfare and appreciation of benefits
(b) fair-weather friends and true friends
(c) beneficial friends and costly friends
(d) ecological conditions for reciprocating and the benefits of deferring investment
(a) the adaptive problem of determining what characteristics one must obtain to occupy a specific
niche
(b) the adaptive problem of deciding how many friends occupy different niches and terminating
as friends those that occupy more than one slot
(c) the adaptive problem of deciding how many slots are available in the group
(d) the adaptive problem of deciding who will fill limited friendship slots
33. Bleske and Buss found that ________ evaluated the potential for sexual access to their opposite-sex
(a) men; more
(b) women; more
(c) both men and women; equally
(d) both men and women; not
(a) groups of three or more individuals with the purpose of increasing the reproductive success of
all members of the group
(b) alliances of more than two individuals for the purpose of collective action to achieve a
particular goal
(c) alliances that are long-lasting and are characterized by mutual engagements among members
(d) a group of several individuals with the goal of cooperating to achieve one member’s goal
(a) previous or current involvement in the military was the best predictor of punitive sentiments
towards participation in a cooperative coalition
(b) defection from groups is a greater adaptive problem than free riding
(c) the best predictor of punitive sentiments was the degree of a person’s own participation in a
cooperative coalition
(d) the less a person was willing to participate in an activity, the more that person wanted to
punish those who could have participated but refused to do so
36. Among the Shuar in Ecuador, punishment is especially harsh toward in-group members who
(a) flaunted their cooperation
(b) cooperated the most
(c) were unable to cooperate
(d) did not cooperate when they could
(a) Observing an unfair game player receiving physical pain activates the brain’s reward centers.
(b) People who do the punishing and remain anonymous to the person being punished tend to
punish cooperators more often.
(c) The reward centers in women’s brains tend to show higher activation levels in response to
witnessing punishment than the reward centers in men’s brains.
(d) Younger men tend to punish female non-cooperators more than older men.
38. What is the hypothesized process by which transmitted ideas, beliefs and values spread because of the
(a) sexual selection
(b) meme selection
(c) cultural group selection
(d) strong reciprocity
39. In order for cooperative coalitions to emerge, individuals must be able to solve all of the following
(a) coordinating individuals toward a common goal
(b) detecting altruistic members
(c) imposing group obligations on members
(d) punishing free riders
(a) of their rarity in the population
(b) they tend to be young women
(c) they tend to be young men
(d) the ability to cheat and get away with it is an attractive quality in a mate
(a) Being primed with thoughts of an experience in which one was cheated causes individuals to
detect cheaters more effectively.
(b) People show heightened memory for cheaters, but this does not result in behavioral changes
during economic games.
(c) People show enhanced source memory for cheaters’ faces.
(d) People remember the faces of low-status cheaters better than the faces of cooperators.
42. Studies have documented that their participants pay more attention to, and better remember, faces of
people who actually cheated in the past—even when the participant is unaware of whether the target
(a) people who cheat look different than people who cooperate
(b) people who cheat are more attractive than people who cooperate
(c) people have a difficult time discerning cheaters from cooperators when they are aware of whether
the target cheated or not
(d) people are afraid to consciously identify cheaters
(a) eyebrow raises
(b) large eyes
(c) femininity
(d) genuine smiles
(a) toward cousins and other distant relatives
(b) in situations where both we and the target benefit from the act
(c) when the target of our altruism cannot reciprocate
(d) none of the above
(a) increased status
(b) increased cooperation from group members
(c) higher quality mating opportunities
(d) all of the above
(a) When engaging in an altruistic act, we tend toward the least costly option regardless of context.
(b) When behaving altruistically anonymously, we are more likely to choose a low-cost option.
(c) In the presence of strangers, we do not behave altruistically.
(d) When volunteering publically, we typically choose the least costly option.
(a) the highest-ranking individual in the social hierarchy
(b) the lowest-ranking individual in the social hierarchy
(c) an individual who highly values you as a friend
(d) your most attractive same-sex peer
48. Which of the following as been hypothesized to underlie the differences documented between how
(a) women’s tendency to mate exogamously
(b) men’s higher frequency of homosexuality
(c) men’s relatively higher paternal investment than other mammalian species
(d) all of the above
(a) antagonistic
(b) costly
(c) intimate
(d) task-based
(a) one witness
(b) a punishment cost
(c) a hunting-related cue
(d) high-tempo music