In this blog post, we’ll examine how communication affects people’s altruistic behavior, focusing on public goods game experiments.
The Paradox of Altruism
Generally, the term “selfish” refers to behavior that pursues one’s own interests, while “altruistic” refers to acting for the benefit of others. Intuitively, people who act for the benefit of others seem desirable, but from an evolutionary perspective, altruistic behavior can be disadvantageous for survival and reproduction. For example, if one person hoards a limited amount of food, they are more likely to survive longer than if they shared it. This raises the question: Why does altruism, which appears evolutionarily disadvantageous, exist?
There are several hypotheses that attempt to explain this. The most prominent include the kin selection hypothesis (benefiting relatives to spread one’s genes), the reciprocity hypothesis (mutual aid leads to mutual benefit), the “birds of a feather” hypothesis (people with similar tendencies gather together), and the communication hypothesis. This article focuses on explaining the “communication hypothesis.”
Overview of the Communication Hypothesis and the Public Goods Game
The communication hypothesis argues that communication between people increases the frequency of altruistic behavior. In other words, by building trust and sharing norms through dialogue, individuals are more likely to act in the interest of the community as a whole, even if they suffer a short-term loss. One of the experiments designed to test this hypothesis is the public goods game.
The public goods game illustrates the problems that arise when multiple people use a limited resource. If overuse—often stemming from the mindset that “it’s okay if just I do it”—is repeated, the total resources are quickly depleted, causing harm to everyone. This is also known as the “tragedy of the commons.”
The specific experimental setup is as follows. Participants form teams of five and are asked to select the amount of resources they can harvest at a time, ranging from 1 to 8. The game is repeated 20 times, and in each round, the system is calibrated so that the greater the total amount of resources chosen by individuals within a team, the smaller the actual benefit each individual receives. Under these rules, if an individual acts selfishly, choosing 8 in every round appears to yield the greatest benefit on the surface; however, if everyone does so, the total benefit plummets. Conversely, if everyone chooses 1, the benefit to the entire community is maximized.
The experiment was conducted in three ways. First, a group that completed 20 rounds consecutively without discussion; second, a group that held a single discussion after 10 rounds and then continued with the remaining rounds; and third, a group that held a discussion after every round starting from the 10th round.
Experimental Results and Interpretation
In the first method, participants tended to collect an average of about 4 to 5 units of resources per round. This is an intermediate level—lower than complete selfishness (8) but still some distance from the maximum collective benefit (1).
In the second approach, participants’ resource extraction decreased significantly immediately after the discussion. In other words, once brief communication took place, they showed a tendency to shift toward altruistic behavior. However, since discussions were not resumed afterward, they gradually reverted to selfish choices as time passed.
In the third scenario, as discussions continued after the 10th round, participants’ resource extraction showed a steady downward trend. This can be interpreted as evidence that repeated communication helps maintain altruistic norms.
Taking these three results together, we can conclude that communication promotes cooperative and altruistic behavior among participants when it occurs in the short term and on a repeated basis. It becomes clear that while a single conversation can bring about temporary change, sustained communication and reaffirmation of norms are necessary to maintain its effects.
Significance, Limitations, and Contemporary Implications
The communication hypothesis offers practical implications suggesting that face-to-face interactions or the exchange of opinions can increase the level of cooperation within a group.
In particular, structuring communication in organizational meetings, when establishing community norms, and in collaborative projects can lead to greater collective benefits.
However, this hypothesis alone cannot explain all forms of altruistic behavior. Small acts of kindness, such as making a spontaneous donation on the street, or anonymous donations of large sums of money, cannot be adequately explained by communication alone. Such behaviors are likely linked to a complex interplay of factors, including other motivations, norms, personal beliefs, and the pursuit of reputation.
Nevertheless, since people today often meet, communicate, and live together, the Communication Hypothesis serves as a useful theoretical tool for understanding cooperation and the pursuit of the common good in modern society. The idea that individual conversations come together to form norms, which in turn shape behavior, is a simple yet important insight.
