Altruism in humans - what makes us special?

Microorganisms, meerkats, and monkeys - they all behave altruistically for different reasons - but what about us humans? Is there anything unique among us humans when it comes to altruistic behaviour? Katie Haylor spoke to Sander van der Linden, from Cambridge University....

Sander - I think when it comes to human altruism there is a defining feature. Whereas in biology it’s about increasing the fitness of an organism at the expense of your own fitness, so your own potential to reproduce genetically. With humans it’s all about psychological motivations that we have to disentangle, so what are the motivations for helping someone else? And I think that poses a fundamental problem to try and figure out how altruistic we are exactly in different situations.

Katie - How do we explain the random acts of kindness, the good samaritan? Say Wesley Autrey we heard about before who dived in front of a train to help that person he didn’t know, how do we explain that?

Sander - Yeah, that’s a great question. We’ve heard about kin selection: sometimes we help other people because they’re just genetically related. We’ve heard about reciprocal altruism: scratch my back, I’ll scratch yours. But what about those cases where you’re not going to interact with a stranger ever again, why would you be incentivised to help that person?

I’d like to split that out into two motives: an individual motive which is that a lot of research shows that people derive positive internal benefits when helping other people. When we help other people the heart rate tends to go down, our blood pressure tends to go down and it can have positive impacts on depression. When you put people in neuroimaging scans it shows that the reward centre of the brain lights up in certain situations. Economists refer to this as ‘warm glow,’ and so the idea is that people derive pleasant emotional experiences from helping other people.

The other is more social that we care as a group-living species we care about our image. You see this in primates too, but especially in humans we care about our reputation. We want to be seen as a cooperative individual who’s going to help and benefit the group. That we’re going to essentially do our bit because that’s an adaptive advantage to have as a group member. This is called image motivation.

Chris - Is this inherited or learned?

Sander - Another great question. We learn about norms in our societies. To some extent this evolves but, on a more simpler level, we acquire norms through social learning. If it’s the norm to help other people, we learn that from other people. Sometimes norms are institutionalised and they get passed over from decade to decade, and even if you talk about cultural evolution over larger time periods. but there’s a lot of variation in culture. The extent to which culture replicates like a gene is a bit more complex but, certainly, we inherit rules and rules of thumb and norms from observing other people.

Katie - This notion of it feels good to do good deeds, does the dopamine reward system come into play here?

Sander - Yeah. Some studies show dopaminergic pathways are activated when people think about donating, for example, or helping other people, and so these ‘feel good’ neurotransmitters are released. Sometimes it’s a bit difficult to disentangle because there’s always other factors that can activate similar neural substrates, and so it’s always a bit difficult to tease out causality but, generally, those factors are associated with helping other people.

Katie - Could the notion of being nice to strangers, could this idea have evolved as a byproduct of it being beneficial to be nice to your friends or your peer group?

Sander - I think it’s difficult to tease out basic mechanisms such as the ability to experience pleasure which is not necessarily related to altruism, even though those mechanisms are associated with, for example, helping other people. Those mechanisms didn’t necessarily evolve solely for that purpose. I think that is difficult to say but, generally, helping other people is adaptive. In a group-living species it’s extremely adaptive if groups are able to cooperate because then they can outperform groups that don’t cooperate, so the fact that these behaviours are adaptive to some extent. I’d like to think, at least, that people on some level recognise that helping other people is adaptive and that that is the reason why it makes us feel good in the end. But, of course, the ultimate answer to that remains somewhat of a mystery.

Katie - If helping others makes us feel good, is there such a thing as a good deed if we’re getting something from it?

Sander - This is one of the questions I always ask my students because this is essentially a game. I can reduce any behaviour to an egoistic motive. If it makes you feel good it disqualifies as true pure altruism. So if you jump in front of a train to help somebody else, if you experience the slightest amount of ‘warm glow’ in that act theoretically it could disqualify as pure altruism. But I think that’s not the key factor because it seems that it would be unrealistic for us to be so altruistic all of the time. I think if we help other people and we feel good about it and there’s a mutual benefit, maybe we should be satisfied with that.