The acts of heroism seen even within seconds of the detonation of the bombs at Boston Marathon included people who seemed to utterly forget fear for their own wellbeing in order to protect that of others. However, Tuesday's events were not first time the world's seen such selflessness before: firefighters and policemen and women during the 9-11 attacks, for example, come to mind for many.
And while for years scientists have struggled to explain such behavior which, for many of us, seems to represent a complete reversal of inborn instincts of self-preservation, a number of new studies have been able to identify how society may have evolved to include such humans.
Emma Seppala, the associate director of the Center for Compassion and Altruism Research and Education (CCARE) at Stanford University, is just one of several pioneers in this relatively new field of study. And the way she sees it, the interpersonal connection that occurs during times of crises may one reason why humans have survived thus far.
Researchers Markus Heinrichs and Bernadette von Dawans of the University of Freiberg, Germany, conducted a study in which male participants were assigned to two groups, one that evoked stress and another that did not. Afterwards, both groups were asked to play an economics game that allowed for financial gain based on different choices. In the game, the participants could choose to cooperate and build trusted allies with other players or not.
Sure enough, those who had undergone a stressful event not only showed more trust, but exhibited more trustworthy behaviors themselves when compared to the control group.
"These findings support the idea that humans have a tendency to provide and receive joint protection within groups during threatening times," Henrichs and von Dawans concluded, according to the Association for Psychological Science.
Furthermore, a study by Benjamin Converse and his colleagues at the University of Virginia found that when people felt out of control, and in particular when they were reminded of their mortality, they were more likely to portray generosity and helpfulness.
Conversely, a research done at Stanford University by Aneeta Rattan and Krishna Savani showed that when people were infused with the feeling of self-determination and control, they were less likely to portray compassion.
"Think back to a time when you felt out of control, for example during a romantic break-up, when you had an empty bank account, or lost a job," Seppala writes on her blog. "Chances are your feeling of vulnerability and feelings of lack of control may have made you seek comfort in others in some way."
Finally, Seppala looks to the example of the nation's men and women engaged in conflicts abroad who, in her research, she says have always expressed a feeling of kinship with those they served with.
"Countless soldiers have perished running into a line of fire to save an inured brother-in-arms," she writes.
Given all of this and her own experiences Seppala suggests that "Acute stress may help remind us of a fundamental truth: our common humanity." This, in turn, she believes, "can inspire kindness, connection, and a desire to stand together and support each other."
The same kindness, connection and desire to stand that the world saw this Tuesday as countless runners and onlookers joined in the fray of Boston's bombings, coming forth with men, women and children in their arms.