The Altruistic Brain

Photo by Elaine Casap on Unsplash

With our divided politics and fierce news media, it’s easy to lose faith in human goodness. Everyone seems to be out to get each other. However, altruism is still a potent force in the world. An altruistic behavior is an action that benefits a recipient but presents some cost or burden to the altruist. We find examples of people who volunteer for charity work and help strangers in need without any obvious expectation of a return favor. Why exactly would we decide to behave altruistically? Is it purely the positive influence of the social institutions we have designed, or are there also altruistic pressures in our biology? Studying the brain can give us some clues.

The brain and the dictator game

Some people are more altruistic than others. Researchers can measure altruistic behaviors in tasks such as “dictator games”, where a participant decides how evenly to split a pool of money between themselves and a second stranger playing the game. Let’s say a participant is given $1200 and offered two options:

  1. Split the money so that you receive $1010 and the other person receives $190
  2. Split the money so that you receive $730 and the other person receives $470

In this scenario, a participant is clearly behaving altruistically if they choose option B. They sacrifice a personal monetary gain in order to give more money to another person.

When participants in one experiment played games like this, researchers found that more altruistic people — those who were willing to give up more — had larger gray matter volumes in a part of their brain called the right temporoparietal junction (TPJ). During altruistic behavior, TPJ activity was highest when the personal costs of altruistic actions were just below the ultimate cost people were willing to pay. If the costs exceeded their willingness, or were much lower than their willingness, their TPJ remained relatively quiet. The anatomy and function of this brain area may therefore relate to how much we are willing to sacrifice. When we realize we need to make a major personal sacrifice, but agree in order to help someone else, our right TPJ is likely to reach its peak level of altruistic activity.

Empathy in altruism

Our motivations to behave altruistically may frequently come from a feeling of empathy. When we see others in pain, we activate similar feelings within ourselves, and this mechanism of empathy seems common across many mammals and birds. It is therefore a strong candidate for explaining part of the story about how altruism evolved. Helping others is rational when we feel as bad as they do, because we also want to get rid of our own negative feelings. Maybe Joey in Friends is right when he argues that there are no selfless good deeds:

https://www.youtube.com/watch?v=ahDxg3hc5pM

Young people today may be familiar with the experience of watching other people play video games. Online video gaming broadcasts attract large followings. The vicarious enjoyment of seeing others play a game may relate to empathy. An experiment in 2007 studied participants’ brains as they either played a simple game or watched somebody else play the game. People who showed greater brain activity during game viewing versus game playing, in an area known as the posterior superior temporal cortex, reported engaging in more altruistic behaviors in their everyday life. These high altruists were better able to link events in the game to the decisions and actions of the game player they were watching. The empathy that allows them to detect intentions and purpose in other people may also bolster their altruistic instincts.

Friendly genes and chemicals

Oxytocin is a chemical produced by the hypothalamus in the brain, and it plays an important role in social behaviors. When oxytocin is administered through the nose, male participants are more likely to trust and cooperate with people within their in-group. With out-groups, they become more likely to be defensively aggressive, for example by engaging in pre-emptive strikes against a group they see as a threat. But they are no more likely to be offensively aggressive in wanting to greedily exploit others. This has been called a “tend and defend” response in an effort to make it as memorable as the “fight or flight” response for adrenaline.

When we are high on oxytocin, we also adapt how we donate money to charities. We become more likely to donate to social charities rather than environmental charities. Experiments have also compared how we spend money on goods when we take oxytocin versus a placebo. Compared to placebo, oxytocin doubles the price we are willing to pay for sustainable goods that are framed in terms of social benefits (e.g. fighting poverty, improving labor conditions). But when sustainability is framed in terms of environmental benefits (e.g. conservation, biodiversity), the price we are willing to pay does not change.

We may find traces of altruism in our genes. Studies on twins allow us to test how much of a particular trait could be explained by genetics versus environment. For example, if identical twins who are reared in separate families happen to be more closely matched on a trait than non-identical twins reared in the same family, that’s a strong sign that genetics plays a major role in defining that trait. According to twin studies, around 50% of the variability in empathy and altruism can be explained by genetics.

Researchers are beginning to find gene candidates related to our altruistic tendencies. Evidence has specifically linked prosocial behavior to genes that regulate hormones including vasopressin and oxytocin. Dopamine — a neurotransmitter recruited in functions such as reward and motivation — also seems relevant to altruism. In one experiment, participants were paid to complete some tough cognitive tasks, and were then asked whether they wanted to donate any of their hard-earned cash to a poor child living in Peru. Participants who carried a specific form of a gene involved in catabolizing dopamine (the COMT gene) donated around twice as much money as the people who lacked that particular form. Social behavior is complicated, so unsurprisingly, the story of altruism seems to involve several hormones, genes, and brain networks.

Extraordinary altruists

The amazing levels of self-sacrifice from some people has earned them the label of “extraordinary altruists”. In academic literature, this label commonly refers to people who donate a kidney to a stranger. This is clearly a tremendous act of kindness: the donor goes through major surgery and takes on health risks in order to save the life of someone they do not know. The brains of extraordinary altruists look like the inverse of a psychopath’s brain. When you compare their brains to a typical population, the altruists have larger amygdalae that are more responsive to fearful facial expressions. Psychopaths have precisely the opposite pattern: smaller amygdalae and less emotional reactivity.

Another recent study from late 2018 took a different approach in analyzing the brains of extraordinary altruists. Kidney donors had their brains scanned while a painful pressure was delivered to their thumb. On some trials, instead of receiving the pain themselves, they watched the pain being delivered to another person’s hand. When researchers examined the levels of activity in the anterior insula of the brain, they found overlapping activity for experiencing pain directly versus watching pain in others. This overlap was greater for the altruists than for typical people. The more reactive their insula was for personally experienced pain, the more reactive it was for empathic pain when watching others get hurt. In other words, evidence consistently shows that altruists have strong indicators of compassion and empathy in their brain, and this predicts their abundant desire to help.

Another group of extraordinary altruists are people who have won a Carnegie Hero Medal for heroic acts as a civilian. Researchers examined the testimonies of medal winners from published interviews, and found that they frequently described acting automatically and intuitively during their moments of heroism. Even when there was sufficient time for them to deliberate over what to do and reflect upon their decision before becoming a hero, their behavior was still dominated by intuition.

This also fits the descriptions of another recent hero, James Shaw Jr, who single-handedly wrestled a weapon away from an active gunman during the 2018 Nashville Waffle House Shooting. Listen to how he describes the quickly unfolding events in the interview below. He does not believe that he should be considered a hero because his actions were instinctive and he was not thinking about saving the lives of other people at the time. But, of course, his courage and life-saving instinct make him a hero regardless of the speed or automaticity of his actions. Heroism does not require deliberation.

https://www.youtube.com/watch?v=ZeKeA21_BFo

What makes an altruist?

Aside from the biological mechanisms underlying our altruism, what influences could drive someone to be altruistic rather than selfish? During one experiment, 1–2 year old children either played reciprocally with an experimenter in a room, for example rolling a ball to one another, or the child and experimenter played with their own separate toys. When the experimenter later needed help with reaching for the object, the children who engaged in reciprocal play were significantly more likely to give them a helping hand. In fact, after reciprocal play with the experimenter, they were also more likely to help another adult who entered the room, suggesting that reciprocal play promotes altruism toward people in general rather than just the people we play with. Older children around 4 years of age showed similar effects in their behavior. After reciprocal play, they were more generous in distributing stickers between themselves and an experimenter. When interacting cooperatively and reciprocally, children learn to be receptive to the needs of others and act benevolently.

In another study, adults were taught compassion training. They imagined loved ones, strangers, and enemies in their minds, while cultivating feelings of warmth and positivity towards them. A control group instead practiced reinterpreting stressful events from their personal life. After 30 mins of practice a day for 2 weeks, participants who went through compassion training were more likely to spend their own cash to help a victim who was treated unfairly in a game. This enhanced altruistic impulse was mediated by changes in the brain that included the inferior parietal cortex, prefrontal cortex, and connections between the prefrontal cortex and deeper brain structures like the nucleus accumbens that are involved in emotional regulation.

But how do we stop the cheaters?

Altruism only really works when we don’t have a huge group of unfriendly narcissists taking advantage of us. So how does humanity maintain a sense of selflessness when up against those kinds of counter-pressures?

One answer is straightforward: punishment. In fact, punishment itself can also be an altruistic act. Imagine you are working in a group where everyone benefits when each person in the team cooperates. When one person chooses not to cooperate, they may get a larger payoff, but it comes at the cost of the rest of the team. So what can a cooperative team member do to stop that person? One option is to accept a personal cost in order to punish the dissenter. Although both the punisher and the punished take a costly hit, this willingness to altruistically punish leads to greater group cooperation over the long term. It ferrets out harmful cheaters and virtue-signaling free-riders.

Altruists may also have a direct mating advantage. In a 2017 study, participants were entered into a prize draw to win $100, and were asked whether they wanted to donate their potential winnings to a charity or keep them. Participants also completed a questionnaire about their sexual history, including questions about their overall number of lifetime sexual partners. The researchers found that men who chose to donate their winnings reported a greater number of partners from their past. This relationship between altruism and sexual partners did not seem to hold true for women. So, at least for men, behaving altruistically may score you points as a prospective romantic partner.

What are we supposed to take from this?

Altruism has a long and interesting story. We find its markers in our brains, genes, and behavior. Many of our altruistic impulses arise from a feeling of empathy, and our hormones help to drive those experiences. Selfless good deeds may be hard to come by, but why should that degrade the value of our altruistic impulses? Any willingness to help another person is worth respecting and appreciating. Whether you are an extraordinary altruist or just a helpful passerby, please keep doing what you are doing. It would be an understatement to say that you flip frowns into smiles. Many of life’s happiest and most inspiring moments come from the time you did what you could to help.