Just a short month ago, most of us in the West were deeply divided over how to best to handle Covid or how terrible the other political party was. Or Brexit or the EU or climate change or cultural wars over issues like gender. You name it, we argued over it.

Now, virtually overnight, ordinary Westerners around the world have banded together in common cause to help Ukraine, spilling over with generosity in the form of charitable donations, food, army recruits and places to stay.

Charity has suddenly spread like a contagion. And observing all this has made me think of the work of Nipun Mehta.

Mehta was a high-strung, high-octane prodigy who had begun computer programming at the age of seven, entered University of California Berkeley at sixteen, and by his junior year, had already been snatched up part-time by Sun Microsystems, which picked up the tab for his college tuition. Within a few years of graduation, he was being paid a six-figure salary, with stock options and sign-on bonuses thrown in.

Like many of the other successful young turks in the Bay Area around San Francisco, he was riding the wave of the vast potential of the Internet. Almost every one of his friends from Berkeley was growing wealthy overnight.

The entire topic of his friends’ conversation seemed to focus on how they were spending this enormous sudden windfall — who had bought the next house, the latest BMW, whose options in IPOs were better than others.

Mehta also had been driven by the prospect of financial success and brought his passion for winning to the stock market. While still at Berkeley, he began trading stocks on the Internet, playing tens of thousands of dollars every day, refusing to quit until he’d turned a loss into a profit.

In the middle of 1999, Mehta began to have an uneasy sense about the get-rich-quick culture around him – particularly its effect upon himself. At times he felt as though he were drowning in a sea of greed.

A profound lesson was waiting for him in India when visiting an old school chum. He’d taken a ride with his friend on his motorized bike, and as they belted along over the uneven pavement of Mumbai’s back streets, Mehta was overcome by such uncontrollable nausea that he asked his friend to stop while he vomited on the crowded street.

Suddenly, a dirty, emaciated old street vendor appeared, riding past on his bicycle. When he saw Mehta, he stopped, slowly reached into a sack, produced a lemon, cut it in half, and handed half to Mehta gesturing for him to suck on it in order to stop the nausea. From the look of him, it might have been his last lemon, yet he was happy to share it.

Without speaking another word, the old man got back on his bicycle and drove off. He had showed up out of nowhere in time of need, carried out an act of kindness and then just disappeared, without requiring any credit.

Mehta returned to Silicon Valley, determined to re-think his own life.

One evening he invited 20 of his young professional friends to a gathering at his home. He wanted to do nothing less than to shift the current American culture of greed and materialism, he told them.

He invited them to carry out an experiment in the joy of giving on their patch of the West Coast, a part of California with the highest per capita ownership of Ferraris and the lowest percentage of charitable donations in the country.

Mehta had in mind starting a charity that would gift the skills of its volunteers to help other charities and non-profits: management training, web development skills, the expertise to grow a business.

With a few deft bits of programming, they could transform a non-profit into a smooth-functioning organization, which could then advertise its services to the community.

“We’re not here to have fun,” he said. “We’re not here to network,” he told them.

Ostensibly, it wasn’t even for the charities themselves. The ultimate idea was to create a contagion of giving, first by creating the contagion within themselves.

“When generosity is the basic social capital, you see things from a broader perspective,” says Mehta.

Nicholas Christakis, a Harvard sociologist and network specialist who studies behavioral contagion, recently discovered a pay-it-forward phenomenon in social networks. The participants were randomly assigned to a sequence of different groups in order to play a series of games with strangers.

Christakis and his partner, James Fowler, drew up networks of interactions, so that they could explore exactly how the behavior spreads from person to person along the network.

They discovered a scientific demonstration of what Mehta has hoped to achieve: spontaneous generosity creates a contagion of giving, a network of “pay-it-forward” altruism. The actions of participants affected the future interactions of other people along the network.

“If Tom is kind to Harry, Harry will be kind to Susan, Susan will be kind to Jane, and Jane will be kind to Peter,” writes Christakis.

All it took was one act of kindness and generosity to spread up to three degrees along the network. So for every act of kindness or generosity you do for a friend, he or she pays it forward to their friends and their friends’ friends and their friends’ friends’ friends.

Christakis proved that Mehta’s instincts were correct: kindness and generosity create a cascade of cooperative behavior, even in the most hardened of hearts.

One of Mehta’s experiments was to see if a business could run entirely on the generosity of the customers. He persuaded the owner of Taste of Himalayas Restaurant, a traditional Indian restaurant in Berkeley, California, to allow CharityFocus to take over the restaurant every Sunday lunchtime.

There are no prices on the one-page Sunday brunch menu; the check at the end reads: $0.  A note is attached at the end, which says: “Your meal was a gift from someone who came before you. To keep the chain of gifts alive, we invite you to pay it forward for those who dine after you."

Diners may pay whatever they wish, and the amounts are kept anonymous.

Karma Kitchen, as Mehta called it, then opened its second restaurant at the Polo India Club in Washington, D.C.

Both restaurants have received more than they would if they charged for meals.

Volunteers travel from all across the world to help out as staff, just to experience service with no strings attached. After basking in the experience of an unconditional gift, many diners are moved to tears. They hug the other diners, and leave notes and poems, as well as money.

Almost everyone asks of the volunteers, “What can I do? How can I help?”

But it’s the look on their faces that speaks the loudest. It’s as though they have just been reminded of a favorite, half-forgotten tune.

Yes, this is it, they seem to be saying: this is what it means to be a human being.

As all we ordinary people in the West are learning now with our deep desire to help Ukraine: when generosity is the currency, the game starts changing.