Hard-wired to give?

Science examines love and extraordinary altruism

We all know the greatest two commands: we are to love God and love each other. Have you ever considered whether love has a biological basis? That some may be born better lovers?

Scientists have started asking these questions about altruists – individuals who act in a costly manner to benefit others. Although not the same thing, love and altruism certainly are connected. Jesus said, after all, “Greater love has no one than this: to lay down one’s life for one’s friends” (John 15:13). In particular, neuroscientists have started to ask if and how the brains of “extraordinary altruists,” such as those who donate a kidney to a stranger, are different from the average person.

In a study published in the Proceedings of the National Academy of Science, Marsh and associates compared the brains of 30 kidney donors with brains of a similar group of normal, matched-control individuals. They used functional magnetic resonance imaging (fMRI) and behavioural tests. fMRI is a scanning technique that permits scientists to make a three-dimensional reconstruction of a person’s brain and observe which parts of it are more and less active in real time, while the person is engaging in a particular task. fMRI is a more complex version of MRI machines used in hospitals to look at a person’s organs to diagnose diseases or other medical issues. The behavioural tests in this study involved people looking at pictures of faces which expressed fearful, angry and neutral expressions. These pictures have been widely used in psychology, and individuals are able to identify the emotion shown in these faces with a fair degree of accuracy.

In Marsh’s study, fMRI scans revealed some very interesting, specific differences in the amygdalae of the extraordinary altruists and normal individuals. Amygdalae are areas of the brain (one amygdala on each side, with slightly different functions) important in processing emotional stimuli. Researchers found that the right amygdala was larger in the altruists than in the control group. The altruists were also better than the average individuals at recognizing fearful faces because of increased neural activity in the right amygdala. When looking at angry faces, the two groups exhibited no difference.

Genetic links

What makes these results particularly interesting is that the exact opposite phenomenon is known to exist in psychopaths: they exhibit a smaller right amygdala and poorer recognition of fearful faces. Psychopaths are anti-social individuals defined by an uncaring nature with deficiencies in pro-social emotions such as guilt, remorse and empathy. Psychopathy has a genetic linkage but is also influenced by environmental factors in development and experience of brain trauma.

The opposite behavioural and brain characteristics seen in extraordinary altruists and psychopaths suggest there is a continuum of caring and that this continuum may be reflected in structural brain differences, particularly in the right amygdala.

One issue this biological approach to altruism raises is the implications for our original connection between love and altruism: does love also have a biological basis that should affect how we think about the command to love? Maybe some people have an easier time to love their neighbour because of the way their brains are wired.

Three things need to be considered at this point. First, it is sometimes unclear whether brain differences cause behavioural differences or if the behavioural differences change the brain. We know there is considerable flexibility in our brain structures.

Second, biology is not destiny. Dogs and cats may be natural enemies, but they can be trained to enjoy being part of the same family. In the same way, there are circumstances, such as brain trauma and bad childhood environments, which can increase the likelihood of psychopathology. And not everyone with a large right amygdala donates a kidney; there must be environmental factors that increase people’s altruism.

Finally, we need to consider the command not to judge our neighbour, as well as the parable about the different number of talents given to each servant. Perhaps the biological difference among people can be thought of as differences in the number of talents we are given. Some people may be given an easier time to love, others an ability to be a teacher. We are charged to be faithful and to ask God to help us love as he commands to the best of our ability, not to judge how God is working with our neighbour.


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