Way back in 1983, Cyndi Lauper knew that "money changes everything." Social science is finally starting to catch up.

The latest findings, from Emily Bianchi of Emory University and Kathleen Vohs of the University of Minnesota, illustrate how having more (or less) money can radically alter the fabric of our relationships with other people, changing how often we socialize — and with whom.

In examining several decades of household survey data, Bianchi and Vohs find that as people make more money, they spend less time socializing with others; they spend more time alone. And when they socialize, they spend more time with friends than with family members or neighbors.

There's a fairly robust body of research showing that "having or thinking about money appears to heighten self-reliance and dampen attention and responsiveness to others," as Bianchi and Vohs put it. In lab experiments, people who are primed to think of money become more motivated to work and less interested in socializing. Exposure to money diminishes compassion toward others. Wealthy people tend to disengage from social interactions.

Bianchi and Vohs take these findings out of the lab to see whether they hold up to real-world observation. They first looked at nearly 30,000 responses to the General Social Survey (GSS) to trace how household income affects respondents' social interactions. The GSS has repeatedly asked Americans how often they spend a "social evening" with relatives, neighbors and friends. Those questions draw a fairly robust portrait of Americans' social interactions. Bianchi and Vohs controlled for age, race, gender, marital status, household size, city size and hours worked to isolate the effect of money on relationships.

The first thing they found was that people with higher incomes spent less time socializing overall: Compared to a low-income individual (earning $5,000 a year), a person from a higher-income household ($131,000 a year) spends, on average, 6.4 fewer evenings each year socializing with other people — even after controlling for differences in hours worked.

Not only that, but when wealthier people socialize, they do so with different people: "People in households with higher incomes spent significantly less time with relatives and neighbors and significantly more time with friends," Bianchi and Vohs found.

Compared with people in the bottom 25 percent of household income, higher-income people (top 25 percent) spent an average of 4.6 fewer evenings with family and 8.3 fewer evenings with neighbors each year. But when it came to friends, the situation was reversed: Higher-income people spent about 5.2 more evenings with friends than their low-income counterparts. And those gaps get even wider as you move farther out on the income spectrum, as the chart above shows.

But why?

There are a number of potential explanations. Bianchi and Vohs note that family members and neighbors provide each other with tangible forms of social support: Your parents might give you financial support for large purchases, or you might rely on a neighbor to mow your lawn or fix your washing machine in a pinch.

"For people with limited financial resources, these social ties are likely to be crucial for managing existing and impending challenges," they write.

If you rely on this type of support from family and neighbors, it's in your interest to cultivate these relationships — Mom's not going to help you with that TV purchase if you haven't visited in five years.

But people with financial means don't need to worry about this as much. They pay a guy to mow the lawn, and if the washing machine breaks, they can either pay someone to fix it or simply buy a new one. Being rich means you can spend your time with who you want, when you want — and that might mean that you spend more time cultivating friendships you've built based on shared values and interests. "Money frees people to be socially connected with those they choose rather than those who can provide resources," Bianchi and Vohs observe.

Social scientists have noticed something of a fraying of the social fabric in recent decades. The number of people saying they have no close friends or family members roughly tripled between 1985 and 2004, and the size of the average close social network has shrunk, too. Robert Putnam famously documented the factors driving these changes in his book "Bowling Alone."

But Bianchi and Vohs's work suggests something else may be at work here as well: Inflation-adjusted household income has risen considerably since the World War II era (even if it's been fairly stagnant in the past decade). And if the relationship between income and social behavior they describe is true, then it's only natural that decreasing social interactions will be one consequence of that change.

Take it away, Cyndi:

These four lifelong friends who were born and raised in D.C. planned to celebrate their 100th birthdays together. (Monica Akhtar/The Washington Post)