Joey: “Well, yeah, it was a really nice thing and all, but it made you feel really good right?”
Friends episode “The One Where Phoebe Hates PBS” (Curtis & Jensen, 1998)
Phoebe: “Yeah. So?”
Joey: “It made you feel good, so that makes it selfish. Look, there’s no unselfish good deeds, sorry.”
Phoebe: “Yes, there are! There are totally good deeds that are selfless.”
Joey: “Well, may I ask for one example?”
Phoebe: “Yeah, it’s… Y’know there’s – no you may not!”
Joey: “That’s because all people are selfish.”
Much of the rest of the episode is spent with Phoebe trying to do a selfless good deed. Regardless of the comedic take of the show, the question itself is important. Is there such thing as a selfless good deed? And if there is, how can this be explained by evolution?
Are humans inclined to behave generously by nature?
The highly regarded book by evolutionary biologist Richard Dawkins, The Selfish Gene, explores two primary explanations for why humans are inclined to behave generously by nature: kin altruism and reciprocation (Dawkins, 2006, p. viii). The overall argument of the book is that selfish genes lead to altruistic behaviors by individuals. In other words, sometimes, the best way to ensure that advantageous genes are passed to future generations (i.e. the gene is selfish because it wants to be passed on) is for the person to help someone else, or to behave generously.
Kin altruism
Genes are not only passed down by a single individual. Humans share significant portions of their DNA with their biological family (i.e. kin). Therefore, another way to ensure that one’s genes are passed on is to ensure the survival of biologically related individuals. Hamilton’s (1963, 1964) rule states that the relatedness of the individuals, or the probability that they share genes (e.g. the probability that siblings share the same gene is ½ and the probability that cousins share the same gene is 1/8), must be greater than the cost benefit ration of the behavior. In other words, an individual is more likely to help their sibling than their cousin, but more likely to help their cousin than an unrelated individual. In reality, we know that humans don’t behave this logically, and that there are innumerable factors that influence individuals’ decisions and behaviors.
In a recent commentary, Aktipis, et. al., (2018) extended this thinking on kin altruism to better explain generous behavior between genetically unrelated individuals. They describe the concept of fitness interdependence, which is a way to understand the extent to which two individuals’ genetic success is intertwined. The authors give a number of examples, including romantic relationships and solders in combat. In romantic relationships, partners are typically dependent on one another to reproduce. In combat, soldiers must rely on their units to survive. While I agree that this is an important part of the explanation of humans’ generous behavior, another important concept to understand is reciprocity.
Reciprocity
Since the publications by Hamilton and Dawkins, among others, researchers have dived deeper into reciprocity to better understand the various conditions that foster generous behaviors and cooperative behaviors. Martin A Nowak described “Five Rules for the Evolution of Cooperation,” in which, in addition to talking about kin selection and group selection, he discussed three types of reciprocity: direct reciprocity, indirect reciprocity, and network reciprocity.
Direct reciprocity is a type of cooperative behavior that is often thought of as person A helps person B, then person B reciprocates and helps person A in return (Trivers, 1971; Rankin & Taborsky, 2009). Indirect reciprocity, where person C helps person A because they saw person A help person B (reciprocity based on reputation; Nowak, 2006), or person B helps person C because person A helped them (upstream reciprocity; Nowak & Sigmund, 2005).
Reciprocity is of particular interest to me in my research. The literature on direct reciprocity and indirect reciprocity based on reputation has grown significantly over the past few decades, there has been less research on upstream reciprocity, which is colloquially referred to as pay-it-forward behavior.
Have you ever been in line at a drive-through coffee shop when the person in the car in front of you paid for your order? Did you pay for the next persons’ order? Why or why not? While some explanations of altruism still fit (e.g. warm-glow; Andreoni, 1990), most other explanations do not. It is unlikely that you know who is in the car in front of or behind you. Therefore, you cannot directly reciprocate (do something for the person in front of you) or receive reciprocation from the person behind you. You may receive some reputational benefit from the employee working at the coffee shop, but given the number of people they serve each day, it is unlikely that this would have any practical benefit. However, paying it forward can make you feel good. Joey may think that “It made you feel good, so that makes it selfish,” (Curtis & Jensen, 1998), but I don’t think it’s that simple.
Therefore, are humans inclined to behave generously by nature? Yes, but is there such thing as a selfless good deed? It depends, particularly on how you define selfless.
References:
Andreoni, J. (1990). Impure altruism and donations to public goods: A theory of warm-glow giving. The Economic Journal, 100(401), 464-477.
Aktipis, A., et. al. (2018). Understanding cooperation through fitness interdependence. Nature Human Behavior, 2, 429-431.
Curtis, M. (Writer), & Jensen, S. (Director). (1998, October 18). The One Where Phoebe Hates PBS. [Television series episode] In D. Crane, M. Kauffman, & K. S. Bright (Producers), Friends. New York City: NBC.
Dawkins, R. (1976). The Selfish Gene. New York: Oxford University Press, Inc.
Dawkins, R. (2006). The Selfish Gene: 30th Anniversary Edition. New York: Oxford University Press, Inc.
Deley, T. (2013). A Selfless Good Deed: Trevor Deley at TEDxCarletonU [Video file]. Retrieved from https://www.youtube.com/watch?v=OvZlGIT1tOA
Hamilton, W. D. (1963). The evolution of altruistic behavior. The American Naturalist, 97(896), 354-356.
Hamilton, W. D. (1964). The genetical evolution of social behaviour. II. Journal of theoretical biology, 7(1), 17-52.
Nowak, M. A., & Sigmund, K. (2005). Evolution of indirect reciprocity. Nature, 437(7063), 1291-1298.
Nowak, M. A. (2006). Five rules for the evolution of cooperation. Science, 314(5805), 1560-1563.
Rankin, D. J., & Taborsky, M. (2009). Assortment and the evolution of generalized reciprocity. Evolution: International Journal of Organic Evolution, 63(7), 1913-1922.
Trivers, R. L. (1971). The evolution of reciprocal altruism. The Quarterly Review of Biology, 46(1), 35-57.