We like to think we’re making our own decisions, but ‘social contagion’ studies suggest we’re more impressionable than we know.
You’re sitting in an airplane munching some almonds and veggies from home and you’re just about to start reading the book you bought specifically for the flight, when the flight attendant stops at your row. He asks if you’d like to purchase any food or movies for the flight. You hold up your book and snack bag and say, “Nope, I think I’m good.” Then the man sitting next to you orders a Bloody Mary and a sandwich, and the woman sitting near the window purchases a pair of headphones and a movie. The flight attendant starts to move on to the next row, when you hear yourself saying, “Wait. On second thought, can I get a beef sandwich, cookie, vodka tonic and a pair of headphones?”
What just happened? Were you hungrier than you thought, or did your decision have something to do with the people sitting next to you? Would you have ditched your book so easily if the woman near the window hadn’t paid for a movie first? Did you just fall prey to social contagion?
Social contagion, also called behavioral contagion, is defined as “the spread of ideas, beliefs and behavior patterns in a group through imitation and conformity.” For centuries theorists have suspected the phenomenon’s existence, but in recent years they’ve gained research-based evidence. Scientists are finding that certain behaviors are like colds and flus: you can actually catch them. Many researchers say social contagion influences many of our decisions, such as whether we make a purchase on an airplane.
A notable study conducted by Pedro M. Gardete, a Stanford business professor, tracked more than a quarter of a million airline passengers and found they are 30% more likely to purchase a movie or snack on a flight if the person next to them does.
This may not seem like too big of a deal, especially when it involves only cheese and crackers during a flight, but social contagion has also been shown to affect other weighty aspects of life — including, literally, weight itself. Using data collected for a three-decade heart study on residents of Framingham, Massachusetts, social scientists Nicholas Christakis and James Fowler found that people were 57% more likely to become overweight if their friends gained weight. More surprising, however, is the correlation they found between two and even three degrees of separation. If a friend of a friend gained weight, a person was 20% more likely to gain weight. And if a friend of a friend of a friend put on extra pounds, a person was 10% more likely to do so. Christakis and Fowler summarized their findings in the book Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives.
Social contagion has even been known to affect divorce rates. In research conducted at Brown University, researchers analyzed three decades of data and found that participants were 75% more likely to end their marriage if a friend got divorced, and 33% more likely to become divorced if a friend of a friend was divorced.
While it’s unclear how exactly the “infection” can skip the connecting person, social scientists theorize that it may have something to do with normalizing behavior. For example, while your coworker might smoke cigarettes but you don’t, you might become more accepting of smoking and somehow transmit that acceptance to your loved one, who might sense a sort of unconscious permission from you, as you would not notice or say anything about their smoking.
While the effects of social contagion have been noted in relation to smoking, drinking, and gaining weight, it also carries power reversely, such as the social contagion of quitting smoking, quitting drinking, losing weight, or even raising levels of happiness. It’s well known that laughter can spread around a room like wildfire, but research shows that the emotion of happiness itself can also be passed from person to person. In a 20-year study of over 4,700 people, researchers found that individuals were able to influence levels of happiness in others within their social network by up to 34%. And once again, the “friend of a friend” principle holds true, as friends of friends were 15% more likely to be happy and then again tapering off at 10% for a friend of a friend of a friend. Interestingly, the study found a slight ability for people to pass unhappiness along, but it is actually far easier to spread happiness than unhappiness, according to the data.
It is actually far easier to spread happiness than unhappiness, according to the data.
While some critics wonder how much other factors, such as environment and homophily (one’s tendency to surround themselves with people who are similar to themselves) affect correlations from the Framingham research, most researchers do believe in the existence of the phenomenon — just not the 100% proof that other factors aren’t also at play.
Whether or not other factors are in the mix, the Framingham studies certainly show a statistical correlation when it comes to behavior among friend groups — and the behavior does appear to be “catching.” Many psychologists have adopted the concept of social contagion. Harvard psychologist Susan David includes a section on social contagion in her book Emotional Agility and says it even has implications for whether we end up following our own dreams.
David says social contagion can leave us feeling as if we are living someone else’s life. In an interview on The James Altucher Show podcast, David says, “We can often end up being in a place in our lives where we turn around and we say, ‘How did I get here?’ I was just going on with the flow. I was just doing what everyone else told me to do.”
David says that “just going with the flow” on autopilot drains purpose from your life and almost guarantees a life void of intention. And this may keep you from accomplishing what you want in life. Or it may cause you to make decisions that seem well thought out but don’t actually serve you, such as the decision to purchase a beautiful home two hours from where you work without acknowledging that the long drive will take away from the family time you truly want.
“We expend a lot of energy on these kinds of counterproductive decisions — energy that would be better put toward achieving our goals.”
So is there any protection against social contagion, or are we just destined to follow the flock?
Susan David says yes, there is an antidote: our values. She explains, “If people have done this thinking about what’s important to them, they’re more likely to be resilient, to be protected. You’re more likely to be congruent with how you want to be in the world.”
In her book, she explains that inflexible notions of “right” or “wrong” values do not help us. Values are less about “rules” and more about purposeful actions that we can bring to all facets of life. Identifying what’s important to us gives us a “priceless sense of continuity.”
David suggests writing a letter to your “distant self” about what you want to accomplish. She says studies show this practice can influence your current decisions.
As a starting point for value discovery, David suggests asking yourself the following questions:
Deep down, what matters to me?
What relationships do I want to build?
What do I want my life to be about?
How do I feel most of the time? What kinds of situations make me feel most vital?
If a miracle occurred and all the anxiety and stress in my life were suddenly gone, what would my life look like and what would I pursue?
Are there particular areas in which people constantly seek my advice and expertise?
Is there a time when I feel “most myself”?
David stresses the importance of searching for your values. “When you know what you do care about, you can be free from the things you don’t care about.”
So perhaps the next time you find yourself on a flight with a good book and bag of packed snacks, you’ll remember you value literature, healthy eating and saving money, and you’ll find yourself sticking with your original plan. Or you’ll remember you value red wine and connecting with new people, and you’ll order a Cabernet and start up a conversation with a nearby passenger. The point is, you’ll make your decision regardless of what the person sitting next to you does.