Summary of:
Brown, W., & Moore, C. (2000). Is prospective altruist-detection an evolved solution to the
adaptive problem of subtle cheating in cooperative ventures? Supportive evidence using the
Wason selection task. Evolution and Human Behavior, 21(1), 25-37.
Summary by Lara Heisser, Jennifer Lambert, and Nisha Patel
For Dr. Mills’ PSYC 452 class, Spring 2010
Evolutionists define altruism as a behavior that reduces the fitness of the donor and
increases the fitness of the recipient. Researchers Brown and Moore (2000) wanted to gain
knowledge about altruism between non-kin. In order for altruistic behaviors to have evolved,
there must have been some benefit for the donor. This is where reciprocal altruism comes into
play; people may incur a cost if there is a chance that in the future, the person who was helped
may perform an altruistic act towards the helper. Reciprocal altruism is then likely to evolve
when subtle cheating is detected. These subtle cheaters are therefore guarded against the people
who perform altruistic acts. The Prisoner’s Dilemma then shows that even though there may be
free-riders, reciprocal altruism can remain fairly stable by using the Tit-for-Tat strategy (Brown
& Moore; 2000, p 26). The Tit-for-Tat strategy calls for cooperation on the first move and then
copying each move made by the opponent; and this strategy can only evolve when cheating is
detected (Brown & Moore, 2000, p 26). The Wason selection task supports cheater detection by
requiring a person to seek out the individual who takes the benefit but does not pay the cost.
Researchers then argue that prospective altruist-detection could be a possible mechanism to solve
the problem of subtle cheating before cheaters are exploited by genuinely detecting altruistic
intentions before a cooperative venture (Brown & Moore, 2000, pp 26-27).
To test the theory of prospective altruist-detection, researchers utilized the Wason
selection task to determine whether a helpful act was motivated by genuine concern. The
structure of the altruistic Wason task was as follows after asking the subjects who they would
sooner trust, “If X helps, then X seeks credit” (Brown & Moore, 2000, p 27). Participants were
allowed to choose any of the following choices: (1) “X helps”; (2) “X does not help” (3) “X does
not seek credit”; and (4) “X seeks credit” (Brown & Moore, 2000, p 27). The correct answer for
a truly altruistic act would be X helps and X does not seek credit. Researchers conducted two
experiments to see if the Wason selection task supported the altruist-detection theory and to
compare altruist-detection and cheater-detection.
Experiment one involves the abstract Wason selection task versus the altruist-detection
task. Subjects were from Introductory Psychology classes and were assigned three problemsolving tasks. One task involved the abstract Wason selection task whereas the other two
involved the altruist-detection act. Problem one of the altruist-detection task involved an
imaginary situation where the participant was seeking a genuinely altruistic babysitter and
problem two involoved choosing a friend to help the participant adjust to the city without taking
advantage of them. The altruist-detection acts were also switched between the participants so
they were detecting motives instead of reasoning logically (Brown & Moore, 2000, p 28). All
subjects received the standard abstract version; and half of the participants received the standard
version of the altruist-detection problem one and the switched version of altruist-detection
problem two whereas the rest of the participants were switched. The results showed that most
subjects detected the altruist regardless of the information that was given to them. Subjects also
performed better on the altruist-detection task than the abstract Wason selection task since
people typically perform better with familiar content (Brown & Moore, 2000, p 30). The
combination of cards reflected the true altruist.
For the second experiment, researchers were testing the difference between the cheaterdetection model and the altruist-detection model. The cheater-detection model was as follows:
“If X receives the benefit, then X must pay the cost” (Brown & Moore, 2000, p 31). Subjects
were then asked to see who was violating the rule. The correct response for the cheater-detection
task would be “X takes the benefit” and “X does not pay the cost” (Brown & Moore, 2000, p 31).
The problem used in experiment two involved legal drinking age. The altruist-detection act was
the same problem used in experiment one. There was no significant difference in performance on
the altruist-detection task versus the cheater-detection task.
The findings suggested that subjects detected altruists despite logic based on the fact that
humans are sensitive to information regarding genuineness of an altruistic behavior (Brown &
Moore, 2000, p 33). Humans have the capability to detect individuals to exploit and altruists who
are genuine may be the people who signal exploitation and are the ones who are therefore taken
advantage of (Brown & Moore, 2000, pp33-34). However, if an altruist can detect a “cheater”
they can form partnerships to avoid being exploited (Brown & Moore, 2000, p 34). With this
information, evolutionary psychologists argue that altruist-detection is an important concept. An
altruist gains the inclusive fitness benefits when they perform genuine altruistic acts which will
help them in the future.
Outline:
I.
II.
III.
IV.
Background
a. Altruism- behavior that reduces the fitness of the donor and increases the fitness of the
recipient.
b. Reciprocal altruism occurs when withholding reciprocity is detected and punished.
i. Prisoner’s Dilemma
1. Strategy where one cooperate’s unconditionally in the first move and
then behaves cooperatively as long as the opponent does so as well.
2. Detecting a cheater requires a person to look for someone who takes
the benefit without paying the cost
ii. Wason Selection task
1. Evidence for cheater-detection
2. Involves identifying cards, “If P, then Q”
Experiment 1
a. Control versus Altruist-detection
b. Three problem solving tasks involving if P then Q statements
i. Problem 1: Wason Task
1. Abstract, involved letters and numbers
2. Used as a control to determine frequency of correct choices.
3. Correct answer: P and Not Q, for “If P, then Q”
ii. 2 Altruist-detection problems:
1. Problem 1
2. In need of trustworthy babysitter who volunteers to help the sick
children for the sake of helping rather than seeking gain
3. Problem 2:
4. The same concept as the previous problem, but the content changes to
giving blood and accepting payment.
iii. Problems were switched to make sure subjects were detecting motives rather
than reasoning logically.
iv. Subjects detecting altruists would choose seeks credit and does not volunteer
c. Subjects detected the altruists and it was not mediated by logical reasoning since the
problems were switched
Experiment 2
a. Altruist-detection versus cheater-detection
i. Altruist-detection
1. Same as experiment 1
ii. Cheater detection problem
1. “If X receives the benefit, then X must pay the cost”
2. Benefit accepted, cost not paid: cheater
b. No significant difference in performance of altruist-detection and cheater-detection
Overall
a. Switching response elicits that subjects are searching for altruists
b. Participants did not solve cheater-detection tasks better than altruist-detection tasks
c. Purpose of the altruist-detection task was to determine genuineness before the act was
performed rather than after