Research shows your social networks affect your mood — and your decisions

The New Year can feel like the perfect opportunity to reinvent yourself — many people decide to go to the gym more often or to eat healthier foods. However, even with the greatest of intentions, New Year's resolutions can be hard to keep.

But some fascinating new research into the science of decision-making may help us better understand why we make the choices we do, and why we sometimes struggle with even our best New Year’s resolutions.

“One of the most interesting findings to come out of a lot of the recent research in labs across the country and even overseas is that there’s really a separation between what we intend to do and how decisions are actually made,” says Kara Miller, host of Innovation Hub.

According to Yale University professor Dr. Nicholas Christakis, a social scientist and physician, it isn't all about willpower. He believes our behaviors are highly contagious and we are unwittingly influenced by those well beyond our social circles.

“We have been able to show, using both observational and experimental methods, that seemingly very personal things like your emotional state or your body size, or how kind you are, or whether you vote or not, depends on whether other people around you do that, and even other people you don’t know,” Christakis said in a recent interview.

Christakis says the behaviors assumed by people in any given social network can have a large ripple effect and impact people who have no relationship at all. Miller says Christakis has long-studied social networks and first observed the rippling behaviors with the so-called “widowhood effect.”

The Harvard School of Public Health defines the “widowhood effect” as “an increased chance of dying after a spouse dies.” Miller says that Christakis’ research finds that this effect can also ripple through a social network.

“He found that it wasn’t just spouses (that died), it was friends of spouses, and friends of friends of spouses,” says Miller. “People who didn’t even know the original spouse who was deceased ended up becoming sick as a result of someone that they didn’t know becoming sick and passing away.”

Though research on decision-making can be helpful for social scientists and medical professionals, Miller also says that businesses are cashing in on the latest data.

“Marketers are picking up on this,” she says. “You have very new companies that are actually looking through Instagram photos and trying to figure out some of these networks and emotions.”

But it’s not just our networks of friends that can influence our decisions. According to Jennifer Lerner, a professor of public policy and management at Harvard University, our own brains can undermine our decisions, too.

Lerner showed individuals footage from sad films, or had people write about something sad. After going through that experience, the subjects in the experiment completely changed their decisions.

“We find that people will sell their possessions for significantly less money when they’re sad than they would in a neutral state because they’re eager to get rid of it, and they are willing to pay much more to buy various goods when they’re in a sad state,” Lerner said.

Lerner continues: “We asked them, ‘Did your feelings, as a result of watching that movie clip or writing what you wrote, did your feelings in any way affect your buying price?’ They say, ‘What are you kidding me? No, absolutely not,’ because they think that would be absolutely irrational.”

Though this research may stir some troubling notions about the way we make decisions, Christakis says that there’s a positive side to this, too.

“We are largely products of our social networks, but even if that’s the case, our work also shows that your actions affect others,” he said. “When you make a positive change in your life, when you act kindly towards others, when you vote, when you express joy and happiness towards others, it doesn’t just benefit you — it benefits those people and in fact ripples out and could affect many, many other people.”

This story first aired as an interview on The Takeaway, a public radio program that invites you to be part of the American conversation.