If one word sums up 2020 so far, it's division. A recent study could give us some much-needed optimism.

Results from an experiment conducted by sociologists from The Ohio State University and the University of South Carolina in the US suggest most of us choose generosity even when multiple interests are at stake.

Contrary to how it might feel at times, we humans are wired to be altruistic. Sociological theory even categorises the motivation behind our general niceness into four distinct types.

One is simple reciprocity, where the recipient of a good deed returns the act. It's a classic case of 'you scratch my back, and I'll scratch yours'.

Another type of motivation involves a third party. If you see somebody scratch another person's back, you might want to respond by rewarding the scratcher.

A third category of motivation is when you're a part of the back-scratcher's club, and there's an expectation that scratches in your network will be rewarded.

Lastly, we're motivated by the 'pay it forward' mentality. If you receive a back scratch from a stranger or even see the act being performed, you might be more inclined to find a stranger yourself to scratch.

There's solid evidence that each incentive affects our behaviour at some point in time, but life is rarely all that simple. What if a stranger walks into your club and starts scratching willy-nilly? Or worse, demands a scratch for free?

"We wanted to do an exhaustive study to see what the effects of those motivations would be when combined – because they are combined in the real world, where people are making choices about how generous or kind to be with one another," says David Melamed from The Ohio State University.

To determine whether different motivations can conflict or cancel out, Melamed and his University of South Carolina colleagues Brent Simpson and Jered Abernathy recruited 709 volunteers through Amazon's Mechanical Turk crowd-sourcing platform, and put these people's generosity to the test.

Each was paid an endowment of 10 points for every decision they made in various scenarios designed to contain combinations of motivators to share income. Just to keep them on their toes, one random scenario rewarded volunteers with bonus points at the end.

Those points weren't mere tokens, either. They had a real-world value of a few cents each, potentially adding up to a few dollars over the course of the experiment. Nothing life changing, but the pay was just enough to force volunteers to question the extent of their charity.

A comparison of the scenarios revealed volunteers were largely willing to hand over cash to strangers no matter which combinations of motivation were present, suggesting the different incentives for altruism aren't competitive.

It came as a surprise to the researchers, who thought that the human bias to look after number one might lead to people ranking their motivations.

"If you do something nice for me, I may weigh that more than if I see you do something nice for someone else," says Melamed.

"But we found that all the motivators still show up as predictors of how much a person is willing to give to someone else, regardless of how the differing motivators are combined."

Altruism is a behaviour fundamental to modern society. Yet its evolution and complex dynamics are still something of a mystery.

Civilisation itself probably wouldn't be possible if humans couldn't be nice to people they hardly know.

Knowing just how far our kindness extends, and the circumstances of our generosity, could be crucial for our global civilisation to continue ticking in the future.

This research was published in Science Advances.