The amplifying role of need in giving decisions

Alexander F. Danvers, Joseph V. Hackman, Daniel Hruschka

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Hamilton's rule predicts that altruism should depend on costs incurred and benefits provided, but these depend on the relative needs of the donor and recipient. Rewriting Hamilton's rule to account for relative need suggests an amplifying effect of need on relatedness, but not necessarily other relationship qualities. In a reanalysis of three studies of social discounting and a new replication, we find that relative need amplifies the effects of relatedness on giving in two samples of U.S. adults recruited online, but not U.S. undergraduates or Indian adults recruited online. Among U.S. online participants, the effect of genetic kinship was greater when the partner was perceived to be in higher need than when in lower need. In the other samples, relatedness was associated with greater giving and greater need, but the effect of relatedness was not significantly amplified by need. Need never amplified the effect of social closeness on giving, although it did diminish the effect of closeness in U.S. undergraduates, likely reflecting a ceiling effect. These results confirm predictions from a modification of Hamilton's rule in a sample of U.S. adults, but raise important questions about why they hold in some samples but not others. They also illustrate the importance of understanding how contextual factors, such as relative need, can moderate the importance of common variables used in evolutionary cost-benefit analyses.

Original languageEnglish (US)
JournalEvolution and Human Behavior
DOIs
StateAccepted/In press - Jan 1 2018

Fingerprint

Cost-Benefit Analysis
Altruism
college students
relatedness
Tissue Donors
sampling
altruism
kinship
prediction
need
decision
effect
cost

Keywords

  • Giving
  • Kin selection
  • Need-based giving
  • Social discounting

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Experimental and Cognitive Psychology
  • Arts and Humanities (miscellaneous)

Cite this

The amplifying role of need in giving decisions. / Danvers, Alexander F.; Hackman, Joseph V.; Hruschka, Daniel.

In: Evolution and Human Behavior, 01.01.2018.

Research output: Contribution to journalArticle

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