In this divided world, there is a growing interest in cultivating empathy—in populations ranging from preschoolers to police officers. And for good reason: Studies suggest that, besides increasing kind and helpful behavior and making the world a better place to live, empathy contributes to our relationships and career success.
But where does empathy come from? Is it mostly taught by parents, teachers, and community? Or is it an innate personality trait determined by genetics?
A recent study, conducted by Martin Melchers of the University of Bonn, Elisabeth Hahn of Saarland University, and colleagues and published in the journal Motivation and Emotion, sought to answer these questions. By using multiple ways of measuring empathy in 742 twins and adult siblings, the study provides some new insights into empathy’s origins.
Previous studies on this subject have had mixed results, with estimates for the heritability of empathy ranging from 0 to 70 percent, depending on the participants who were included and the methods used. If a trait is 0 percent heritable, that means that differences in that trait are due solely to environmental differences—the influence of so-called “nurture.” If a trait is 100 percent heritable, that means that all differences observed in that trait across a population can be attributed to genetic variation.
Observational studies of very young children found low estimates of heritability, and these estimates varied depending on the children’s ages. Studies in adults, which have mostly relied on participants reporting their own empathy levels, have produced similarly disparate results, with estimates of the heritability of empathy ranging from 28 to 72 percent.
The study by Melcher, Hahn, and colleagues was the first to address the concern that participants don’t rate their own empathy accurately, by combining self-report surveys with the results from a behavioral empathy test. Specifically, the researchers looked at the heritability of two different subcomponents of empathy: affective empathy, or a person’s ability to feel what someone else is feeling, and cognitive empathy, or a person’s ability to understand another person’s feelings and reasoning.
To do this, Melchers and colleagues compared the similarity in empathy levels between identical twin pairs, who are virtually genetically identical, to the similarity between fraternal twins and other sibling pairs, who are expected to share about half of their genetic background. This way, the researchers were able to determine the extent to which individual differences in empathy are likely due to inherited genetic factors rather than environmental ones.
To quantify the participants’ affective and cognitive empathy levels, the researchers asked them to answer a questionnaire and take the Reading the Mind in the Eyes test, which measures the ability to recognize emotions from faces. Based on the results of these tests, Melcher and colleagues estimate that affective empathy is between 52-57 percent heritable, whereas cognitive empathy is less determined by genetics—about 27 percent heritable, presumably influenced more by environment and learning experiences.
These results are relevant to empathy training programs, the authors note, such as those offered to people with autism, to patients with conduct problems, and to prevent bullying in schools.
“These trainings often try to enhance participants’ ability for perspective taking, following the idea that better abilities in this domain may lead to empathic concern/affective empathy,” write the researchers. Yet differences in the success of this training might be due in part to the heritability of affective empathy, they note—as some people may be more genetically hardwired to feel the emotions of others before even starting such a program.
There are some limitations to this study. For one, it doesn’t tell us about the role of gender in the heritability of empathy. Past studies have found evidence of gender differences, including differences in the neural networks activated by empathy. Another unknown is how exactly measurements of the heritability of empathy might be affected by age—previous studies have found that the heritability of other traits, such as cognitive ability, shows up more strongly in older people. Future studies that measure the heritability of empathy across development might help answer these open questions.