Neurological Basis of Altruismby Viatcheslav Wlassoff, PhD | April 29, 2016
Altruistic behavior is often seen as a hallmark of civilized person. Defined as a selfless concern for the well-being of others, or action/behavior that benefits others at someone’s own expense, altruism was, for very long time, viewed from two opposite perspectives.
Some would argue that altruism is an integral part of human nature, something that is written in our genes. Others would say that altruism is a product of civilizing influence which start to appear in human society with the development of culture and/or religion. The question appears to be mostly philosophical rather than scientific, and indeed it was mostly discussed and analyzed in philosophical and theological circles. Surprisingly, more definitive answer to this question may come from neuroscience. Indeed, recent research findings provide convincing evidences that, to a certain degree, we are biologically programmed to be good and caring of each other.
Altruism is not an exclusive domain of human culture –animals are known to be altruistic. Animals fearlessly defend their youngsters, even when knowing that the offspring belong to other members of the species. Many researchers do not view parental behavior as real altruism, though. In a more convincing experiment, scientists were giving electric shocks to a rat each time when its neighbor was eating food. The neighbor eventually stopped eating! Should we view this as an example of higher level of intelligence and brain development? Neuroscience provides a remarkable answer to this question.
Altruism and charity
In their seminal work published in 2006, Moll and co-authors investigated the human brain activity using functional MRI when participants were making decisions on charitable donations with real money. Anonymous charitable activity is universally seen as an example of pure altruism since individuals donating money can hardly ever expect any benefits, favors or financial gains come back to them.
The main theme of this experiment was to construct a map of the neural pathways involved in the decisions based on self-interests or any kind of altruistic behavior. The participants were provided with the list of charitable organizations and their mission statements, and were asked to donate small amount of their sum to organizations of their own choice so that scientist could study their brain activities. But the experiment involved an additional unusual feature: the money that were not donated would be given to participant as his/her personal monetary reward. Thus, there was a conflict between decisions to donate or to oppose the cause.
Most of the participants made consistently costly decisions donating, on average, 40% of money. Participants also took longer time making costly decisions than non-costly, showing that such decision involves moral emotions in judgment. Activity in different regions of the brain was observed according to the decision of the participant, either involving self-interest or selfless decisions.
Midbrain ventral tegmental area (VTA), dorsal striatum and ventral striatum were activated by both pure monetary rewards and decisions to donate. Donating to social causes activates two regions: VTA and striatum mesolimbic network. This suggests that both donation to societal causes and money earning activate anatomical system of reward reinforcements and expectancy.
The subgenual area (Brodmann’s area 25) was highly specific for decisions involving donations. This area plays an important role in social attachments. Unlike the midbrain VTA, this area was activated in situations where monetary rewards were not expected. The ventral striatum (with adjoining sepal’s region) was seen to be more active for donations rather than pure monetary rewards. The anterior prefrontal cortex was involved in decisions purely involving the benefits of others.
Leaving this anatomical description aside, what these findings demonstrate? The areas of brain that were lighting up during altruistic donations are actually the same ancient parts of the brain that are activated in response to food, sex and material gains. The results suggest that altruistic behavioral traits are hard-wired in the brain, and they are even pleasurable.
Altruism in the pre-frontal cortex
There are many areas in the brain that are responsible for decision making and reasoning. They include the amygdala, somatosensory cortex, anterior insula and prefrontal cortex. The combined effect of processes happening in these areas influences our altruistic behavior. Some areas are more important for decision making while others are involved in empathy, the sympathy for pain and feelings for others. But the most important area of them all was shown to be the prefrontal cortex.
Recent experiments have showed that the prefrontal cortex is responsible for behavioral changes and controlling impulses. In one study, researchers aimed to find out if certain areas of the prefrontal cortex might be involved in blocking the altruistic impulses.
The study participants were subjected to a noninvasive procedure called theta-burst Transcranial Magnetic Stimulation (TMS). This procedure temporarily dampens activity in specific regions of the brain, thus allowing to observe what happens when a specific part of brain is not active.
Those participants in whom the dorsolateral prefrontal cortex was dampened tended to be generous to people with higher income, i.e. those who wouldn’t be in much need of handouts. And in those participants in whom the dorsomedial prefrontal cortex was dampened, there was a tendency to be more generous towards everyone. The findings demonstrate once more that altruism is really encoded in our brain. By nature, we are very altruistic indeed.
Apart from answering the deeply philosophic question about our nature and morality, neuroscience appears to suggest potential new avenues for increasing empathy. This can have far reaching practical applications, particularly for treating people who have experienced desensitizing situations, such as war experience or a period of staying in prison. I won’t be surprised if one day we will have some pills aimed at modifying our character to the better.
Baumgartner, T., Knoch, D., Hotz, P., Eisenegger, C., & Fehr, E. (2011). Dorsolateral and ventromedial prefrontal cortex orchestrate normative choice Nature Neuroscience, 14 (11), 1468-1474 DOI: 10.1038/nn.2933
Christov-Moore, L., & Iacoboni, M. (2016). Self-other resonance, its control and prosocial inclinations: Brain-behavior relationships Human Brain Mapping, 37 (4), 1544-1558 DOI: 10.1002/hbm.23119
Mathur, V., Harada, T., Lipke, T., & Chiao, J. (2010). Neural basis of extraordinary empathy and altruistic motivation NeuroImage, 51 (4), 1468-1475 DOI: 10.1016/j.neuroimage.2010.03.025
Moll, J., Krueger, F., Zahn, R., Pardini, M., de Oliveira-Souza, R., & Grafman, J. (2006). Human fronto-mesolimbic networks guide decisions about charitable donation Proceedings of the National Academy of Sciences, 103 (42), 15623-15628 DOI: 10.1073/pnas.0604475103
Post SG (2005). Altuism, happiness, and health: it’s good to be good. International journal of behavioral medicine, 12 (2), 66-77 PMID: 15901215
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