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Monday, August 30, 2021

Generosity pays: Selfish people have fewer children and earn less money.

Eriksson, K., Vartanova, I., et al.
(2020). Journal of Personality and Social 
Psychology, 118(3), 532–544. 


Does selfishness pay in the long term? Previous research has indicated that being prosocial (or otherish) rather than selfish has positive consequences for psychological well-being, physical health, and relationships. Here we instead examine the consequences for individuals’ incomes and number of children, as these are the currencies that matter most in theories that emphasize the power of self-interest, namely economics and evolutionary thinking. Drawing on both cross-sectional (Studies 1 and 2) and panel data (Studies 3 and 4), we find that prosocial individuals tend to have more children and higher income than selfish individuals. An additional survey (Study 5) of lay beliefs about how self-interest impacts income and fertility suggests one reason selfish people may persist in their behavior even though it leads to poorer outcomes: people generally expect selfish individuals to have higher incomes. Our findings have implications for lay decisions about the allocation of scarce resources, as well as for economic and evolutionary theories of human behavior. 

From the General Discussion

Our findings also speak to theories of the evolutionary history of otherishness in humans. It is often assumed that evolution promotes selfishness unless group selection acts as a counter-force (Sober & Wilson, 1999), possibly combined with a punishment mechanism to offset the advantage of being selfish (Henrich & Boyd, 2001). The finding that otherishness is associated with greater fertility within populations indicates that selfishness is not necessarily advantageous in the first place. Our datasets are limited to Europe and the United States, but if the mechanisms we sketched above are correct then we should also expect a similarly positive effect of otherishness on fertility in other parts of the world.

Our results paint a more complex picture for income, compared to fertility. Whereas otherish people tended to show the largest increases in incomes over time, the majority of our studies indicated that the highest absolute levels of income were associated with moderate otherishness. There are several ways in which otherishness may influence income levels and income trajectories. As noted earlier, otherish people tend to have stronger relations and social networks, and social networks are a key source of information about job opportunities (Granovetter, 1995).