Transcript Williams, S.S. (2007). Altruism of kin vs. non kin: Effects of costs of

Williams, S.S. (2007). Altruism of kin vs. non
kin: Effects of costs of help and reciprocal
exchange. Evolution and Human Behavior,
28, pp. 193 – 198
By David Guzman, Alicia Witter, and Alexa Aftias
Williams, S.S. (2007). Altruism of kin vs. non
kin: Effects of costs of help and reciprocal
exchange.
Evolutionary Theory on Altruism
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Kin Selection Theory
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Inclusive Fitness
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Gene is the driver of evolution
Kin helping the genes in their relatives pass on
Hamilton’s Law
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rB > C
Williams, S.S. (2007). Altruism of kin vs. non
kin: Effects of costs of help and reciprocal
exchange.
Non Kin Altruism: Problems

According to evolutionary theory, kin
altruism should always come before non
kin altruism
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This is because kin share genes
Some studies have shown that non kin
receive as much or more help than kin
Kin do not reciprocate help as much as non
kin
Williams, S.S. (2007). Altruism of kin vs. non
kin: Effects of costs of help and reciprocal
exchange.
Method
295 Participants
Asked participants relationship of the target
individual
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Siblings, cousins, acquaintances, and close friends
Level of cost was pre-selected
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Low-cost was categorized as emotional support
Medium-cost was represented by five items: help during
an illness, crisis, everyday living, with housing, and
financial help
High-cost dealt with a hypothetical situation of either
donating a kidney or risk injury and death to save the
target individual
Williams, S.S. (2007). Altruism of kin vs. non
kin: Effects of costs of help and reciprocal
exchange.
Results
Low cost
Medium cost
High cost
60
50
40
30
20
10
0
Sibling
Cousin
Acq
Williams, S.S. (2007). Altruism of kin vs. non
kin: Effects of costs of help and reciprocal
exchange.
Friend
Help given as a function of help
received for each relationship category
1.2
1
0.8
0.6
Reciprocated
help
0.4
0.2
0
Sib
Cou
Acq
Fre
Williams, S.S. (2007). Altruism of kin vs. non
kin: Effects of costs of help and reciprocal
exchange.
Interesting Points
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Friends received the most help at low cost
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Siblings received less help than friends at low
cost
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But the higher the cost, the higher the help they received
Cousins were low in low cost and medium cost
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But as cost increased, help for friends decreased as well
But high cost (life and death) they sky rocketed up
Acquaintances help in high cost plummeted
Acquintances received the most reciprocated help
Williams, S.S. (2007). Altruism of kin vs. non
kin: Effects of costs of help and reciprocal
exchange.
Discussion
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Evolutionary theory is consistent with non
kin altruism
Emotional attachment is not primary
Lack ofKin Reciprocity: Old generation
passes on to the new
Non Kin Reciporcity: Larger time frame
Williams, S.S. (2007). Altruism of kin vs. non
kin: Effects of costs of help and reciprocal
exchange.
Critical Review
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Strength
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The strength of the study lies in the classification of low,
medium, and high cost helps as determining factors
between kin and non kin.
This method of measuring altruism was very effective and
qualified the levels of cost and willingness to help.
Weakness

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The hypothetical situations for high cost level may have
been a variable on the responses of the participants.
Hypothetical situations only measure what the participant
thinks they would do, not what actually did happen like the
low cost and medium cost conditions.
Williams, S.S. (2007). Altruism of kin vs. non
kin: Effects of costs of help and reciprocal
exchange.