Infants who are more responsive to the emotion of fear in another person’s face tend to become more altruistic toddlers, according to a new study published in the open-access journal PLOS Biology.
Altruistic behavior, such as helping a stranger in need, is considered a key feature of cooperation in human societies. Yet our tendency to engage in compassionate, selfless behaviors varies considerably in our society, ranging from extraordinarily altruistic kidney donors to highly antisocial psychopaths.
Previous research has suggested that greater sensitivity to fearful faces is linked to heightened levels of prosocial behavior. Specifically, a person’s response to seeing others in distress (displaying fear) appears to be a key process related to altruistic tendencies, with kidney donors showing heightened sensitivity and psychopaths showing decreased sensitivity to fearful faces.
At the level of the brain, the amygdala shows diminished responses to fearful faces in psychopaths and enhanced responses in highly altruistic kidney donors.
In the new study, the researchers test the hypothesis that this link exists in the earliest stages of human development. Study leader Dr. Tobias Grossmann and colleagues tracked the eye movements of seven-month-old infants to examine whether their attention and response to seeing emotion in other people’s faces could predict altruistic behavior at 14 months of age.
The findings show that the infants’ attention to fearful faces — but not happy or angry faces — could effectively predict altruistic behavior in toddlerhood. Specifically, infants who showed heightened initial attention to (such as a prolonged first look) followed by greater disengagement from fearful faces at 7 months displayed greater prosocial behavior at 14 months of age.
Moreover, infants’ attentional bias to fearful faces and their altruistic behavior was predicted by brain responses in the dorsolateral prefrontal cortex measured through functional near-infrared spectroscopy.
This suggests that, from the very earliest stages of human development, variability in altruistic helping behavior is linked to our responsiveness to seeing others in distress, as well as brain processes implicated in attentional control.
“These findings critically advance our understanding of the emergence of altruism in humans by identifying responsiveness to fear in others as an early precursor contributing to variability in prosocial behavior,” said Grossmann, of the Max Planck Institute for Human Cognitive and Brain Sciences (MPI CBS) and the University of Virginia, and first author of the paper.
Based on these findings, it can be argued that it is in our nature to be altruists, say the researchers.