Altruism Among Kin vs. Non-kin: Effects of Cost of Help and

Reciprocal Exchange

By: Esmeralda Arrizón-Palomera, Elena Rodriguez, and Alexa Tangalakis

Video Clip: Gorilla Saves Kid

Hamilton’s Kin Selection Theory (KST)

Higher levels of altruism is associated with greater relatedness

Problems with KST Unable to explain data on human altruism

Unrelated acquaintances receive less help than kin, but do receive some help

Certain categories of non-kin are exceptions to the general rule that humans tend to help kin more than nonkin

Friends often receive as much or even more help than kin

Present Study & Purpose

The study explored some of the ways in which the findings can be reconciled with KST. Costs of Helping

Hypothesis 1: As the cost of helping increases, the share of help given to kin will increase, and the share given to nonkin will decrease.

Levels of Reciprocal Exchange: KST in tandem Triver’s Altruism Theory (RAT) Hypothesis 2: The association between help

given and help received will be larger for acquaintances than for friends, and larger for friends than for siblings or cousins.

Method & Procedures Participants Materials

Recruitment: online Received Credit for Participation Completed a booklet of questionnaires titled “Understanding

Behavior” Procedure

one of eight conditions based on sex of the target the relationship

Word Meaning Task had to choose which one of the synonyms was closest to the

original word. Social Relationships

demographic data items related to altruism and were representative of three

categories of help: low-cost, medium-cost, and high-cost help Other Variables

Results Help Given as a Function of Relationship

Category and Cost of Help Hypothesis 1 Findings Hypothesis 2 Findings

Explanations, Limitations, and ConclusionExplanations

Emotional closeness is an evolved psychological disposition that helps to mediate the link between relatedness and altruism.

Communal Relationships Exchange Relationships Cultural Norms

Limitations Weakness in measurement strategy

Assessment of level of reciprocity Comparison between actual helping and hypothetical helping

Conclusion The results constitute good support for an inclusive fitness

approach to explain altruism among humans

Critique: Weaknesses Recruitment

Testing

Actual Helping vs. Hypothetical Helping

Interesting Points

low-cost help, people helped friends more than siblings

Even though young adults report that they are emotionally closer to friends than to siblings, participants were more willing to provide high-cost help to siblings

Test Questions: Multiple Choice 1. One of the ways in which this study attempts to reconcile the

findings about human altruism with Kin Selection Theory is by considering:A. The proximity to the target individualB. Cultural normsC. Age differenceD. Cost of Help

2. According to the article, the category of nonkin that is an exception to the rule that people help kin more than nonkin is: A. Acquaintances B. Friends C. Classmates D. Co-workers

3. The results indicate that ________A. The degree of reciprocity among friends is higher than that among siblings or cousins.B. The degree of reciprocity among siblings is higher than that of friends.C. The degree of reciprocity among friends was no higher than that among. siblings or cousins.D. The degree of reciprocity among cousins was not higher than that of siblings.

True or False4. According to the article, Kin Selection

Theory is able to explain all of the data on human altruism.

A. True B. False5. According to the article, greater

relatedness is associated with higher levels of altruism.

A. True B. False6. According to Stewart-Williams, the cost-

help finding is a product of cultural norms.

A. True B. False

Answer Key:

1. D-Cost of Help2. B-Friends3. C-The degree of reciprocity among

friends was no higher than that among siblings or cousins.

4. B-False5. A-True6. B-False

Reference

Stewart-Williams, Steve (2007). Altruism among kin vs. nonkin: effects of cost of help and reciprocal exchange. Evolution and Human Behavior, 28, 193-198.