Why do people sacrifice their own self-interest for another person?

OK this is what we know:

• We’re more likely to share resources with others when we feel like our lives and work are interdependent
• Collaboration effect operates by creating sense of indebtedness to the collaborator

In a new study published in Nature Human Behaviour, researchers show that people are more willing to sacrifice for a collaborator than for someone working just as hard but working independently.

What the researchers say: “This suggests we’re more likely to share our resources with others when we feel like our lives and work are interdependent with the lives and work of those other people,” said the lead author. The effect appears to exist regardless of how much effort the partner puts in.

The researchers found evidence that this collaboration effect operates by creating a sense of indebtedness to the collaborator.

“When thinking about what might be driving the effect, my hunch was that this was driven by a sense of obligation to your collaborator, rather than just some general sense of goodwill—that people felt like they owed the collaborator something,” the lead author said. “I was surprised by how starkly that was supported when looking into it: Indebtedness really stood out from all the rest of the possibilities.”

Though an impulse to repay a collaborator may be pro-social in many scenarios, the researchers noted that giving preferential treatment to those who have contributed to your social or political cause could have problematic implications for ethical behavior.

“A politician given a generous campaign contribution could feel an innate ‘moral’ compulsion to satisfy a debt owed to the donor, or a doctor receiving a research grant from a pharmaceutical company may feel a similar impulse to ‘give something back,’” she said.

She added that there’s been pioneering work in developmental and comparative psychology suggesting that collaboration in our evolutionary past may have played an important role in shaping an innately human sense of distributive justice—that is, what we consider to be a “fair” distribution of resources.

“Certainly, an impulse to repay a collaborator is a good thing in many scenarios—but giving preferential treatment contingent upon a contribution to your cause has some troubling implications in terms of ethical behavior,” she mused. “Taken together with the work suggesting that collaboration in our evolutionary past may be responsible for our developing a distinctly human sense of justice and fairness, we arrive at this surprising implication: the development of human morality and our vulnerability to corruption potentially springing from the same source.”

So, what? This is hardly surprising if you look at human motivation. Our key motivator is to surround ourselves with a network of supportive relationships. This is the main element in our feeling of safety. We will do whatever is necessary to preserve this network. A collaborator at work, or a donor to our cause, can be seen as a key part of this nexus and so the relationship with that person becomes very important and will be preserved even if it means indulging in unethical behavior.

Any moral erring will be rationalized away, and we’ll feel justified.