Word.ws English Dictionary

green-beard effect

green-beard effect proper noun: a hypothesis in evolutionary biology that explains selective altruism among individuals of a species, involving preferential treatment of individuals with certain characteristics.

Proper noun

green-beard effect

  1. A hypothesis in evolutionary biology that explains selective altruism among individuals of a species, involving preferential treatment of individuals with certain characteristics.

Origin of green-beard effect

From a hypothetical example used in Richard Dawkins' book The Selfish Gene (1976), whereby a person with a green beard acts altruistically towards other people with green beards.

Questions about green-beard effect

What does green-beard effect mean?
Green-beard effect means a hypothesis in evolutionary biology that explains selective altruism among individuals of a species, involving preferential treatment of individuals with certain characteristics.
What part of speech is green-beard effect?
Green-beard effect is a proper noun.

Words near green-beard effect in the dictionary

  1. green-backed gerygone
  2. green-backed gerygones
  3. green-backed tit
  4. green-backed tits
  5. green-bag
  6. green-beard effect
  7. green-bed
  8. green-beds
  9. green-bind
  10. green-binds
  11. green-black

Source and license

Adapted from Wiktionary: green-beard effect (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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