Skip to Content

Altruism Repays the Best-Connected Individuals

Unselfish behaviour spreads through society in a way that most benefits the “hubs” in the network.

How altruistic behaviour emerges has puzzled evolutionary biologists for decades. From the point of view of survivial of the fittest, the unselfish concern for the welfare of others seems inexplicable. Surely any organism should always act selfishly if it were truly intent on saving its own bacon.

One explanation is that altruistic acts, although seemingly unselfish, actually benefit those who perform them but in indirect ways. The idea is that unselfish acts are repeated. So those who have been helped go on to help other individuals, ensuring that this behaviour spreads through a group, a phenomenon known as upstream reciprocity.

Eventually, the individual that triggered the altruistic behaviour will be on the receiving end of least one unselfish act, ensuring that, at the very least, he or she doesn’t lose out. In this way, unselfish individuals actually benefit from their altruism.

At least, that’s the theory. While other types of altruism have been observed and modelled (for example downstream reciprocity in which people help others who they have seen acting altruistically), upstream reciprocity has proven harder to pin down, until now

Akio Iwagami and Naoki Masuda at the University of Tokyo have simulated the way upstream reciprocity spreads through a network when the behaviour gradually dies out. It turns out that the type of network is crucial for ensuring the spread of the behaviour. In heterogeneous networks like those that most societies seem to form, upstream reciprocity seems to spread successfully.

But interestingly, Iwagami and Masuda point out that certain individuals seem to benefit more than others. These individuals are “hubs” in these societies, people who have many links to other individuals. That makes sense, of course, because as this behaviour spreads, it is much more likely to pass through hubs than other points on the network.

So the moral of the story is that if you want to benefit from altruistic behaviour, do two things. First, trigger altruistic cascades by performing many acts of unselfish behaviour. Second, become a hub with lots of links to other indviduals.

Ref: arxiv.org/abs/0905.4007: Upstream Reciprocity in Heterogeneous Networks

Keep Reading

Most Popular

open sourcing language models concept
open sourcing language models concept

Meta has built a massive new language AI—and it’s giving it away for free

Facebook’s parent company is inviting researchers to pore over and pick apart the flaws in its version of GPT-3

transplant surgery
transplant surgery

The gene-edited pig heart given to a dying patient was infected with a pig virus

The first transplant of a genetically-modified pig heart into a human may have ended prematurely because of a well-known—and avoidable—risk.

Muhammad bin Salman funds anti-aging research
Muhammad bin Salman funds anti-aging research

Saudi Arabia plans to spend $1 billion a year discovering treatments to slow aging

The oil kingdom fears that its population is aging at an accelerated rate and hopes to test drugs to reverse the problem. First up might be the diabetes drug metformin.

Yann LeCun
Yann LeCun

Yann LeCun has a bold new vision for the future of AI

One of the godfathers of deep learning pulls together old ideas to sketch out a fresh path for AI, but raises as many questions as he answers.

Stay connected

Illustration by Rose WongIllustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.