Selfish genes or selfish memes: The effect of genetic relatedness versus value similarity on altruism

Two preregistered quasi-experiments disentangled the effects of selfish genes and memes on participants? self-reported willingness to help in hypothetical everyday-favor life-or-death situations. Memes were operationalized as perceived level similarity important attitudes values between person participating study a selected target person, assessed reported by participant. In Study 1 (N = 761), altruism was highest for siblings, then cousins nonkin; greater memetic also associated with altruism; interaction factors not significant. 2 841), conducted during COVID-19 pandemic, but same effect replicated; term remained insignificant. Both studies controlled range demographic social relationship characteristics, suggesting potentially relevant role future contact probability emotional closeness. We propose that, similarly gene selfishness, meme selfishness can bring about altruism: individuals would rather make personal sacrifice memetically similar than dissimilar others because have higher chance spreading helper?s memes.