We not only favor our genes (altruism for those with similar genetics), greater memetic similarity (similarity in important attitudes & values) was associated with greater altruism

Baucal, Aleksandar, and Aleksandra Lazić. 2021. “Selfish Genes or Selfish Memes?.” PsyArXiv. May 5. doi:10.31234/osf.io/c4j92

Abstract: When “selfish genes” and “selfish memes” compete, who would one rather help – an ideologically similar acquaintance or a relative with a different worldview? Two preregistered experiments disentangled the effects of selfish genes and selfish memes (operationalized as similarity in important attitudes and values) on participants’ self-reported willingness to help in hypothetical everyday-favor and life-or-death situations. In Study 1 (N = 364), altruism was highest for siblings, and the same for cousins and nonkin; greater memetic similarity was associated with greater altruism, and the interaction term was not significant. Study 2 (N = 252) replicated this during the COVID-19 pandemic, suggesting the effects are not altered in life-threatening situations. Studies suggest that meme selfishness shapes altruism independently of gene selfishness. This becomes especially important in times of rising social polarization.