Social contagions debunked: Reports of infectious obesity and divorce were grossly overstated.

The state of the universe.
July 5 2011 6:53 AM

Disconnected?

We've heard that obesity and divorce can be passed from one person to another. Critics now wonder how the "social contagion" studies ever passed peer review.

(Continued from Page 1)

But the media world does not, and for the past few years Christakis and Fowler have been happy to race ahead of peer review and feed the news borg with interviews on tasty topics like contagious divorce. The publicity has helped them achieve scientific stardom. They speak regularly to enthusiastic crowds about their network studies and their 2009 book Connected, which has been translated into Chinese, Croatian, Dutch, German, Greek, Hebrew, Hungarian, Indonesian, Japanese, Korean, Polish, Portuguese, Romanian, Russian, Spanish, Swedish, Thai, Turkish and—cheerio!—British English.

Despite their omnipresence, they have argued that their media appearances should be considered distinct from their science. In their draft statistical paper they write, "We do not think that short remarks we have made to reporters (or even on comedy shows, which one critic took us to task for) should be used to evaluate our findings." Yes, I did take Fowler to task for an interview he gave to Stephen Colbert, during which he claimed to have lost a few pounds so as to avoid infecting those around him with excess flab. Yet I only learned of the Colbert appearance after interviewing economist Charles Manski, a lion in the world of quantitative social science, who called it the "low point" for him in the theater surrounding the flawed studies. The problem was not that Fowler was dispensing with scientific precision for a lay audience; the problem was that he was giving unfounded health advice on national television, Manski said. (On the more difficult scientific matter of whether the force field of comedic "truthiness" that envelopes Stephen Colbert also protects his guests, my sense is no, but that question goes beyond the scope of this article.)

Advertisement

Although the social-contagion studies have been media hits, there has been less demand for the debunking stories in the science news marketplace. After the Lyons study was published, a few health and media blogs took note and began to ask why more journalists weren't covering it. People are more interested in reading about new findings than a refutation of those findings, explained Forbes science writer Matthew Herper as the discussion moved to Twitter.

The scientific establishment has the same problem: Outlets for critiques are relatively few and not highly regarded. Consider that Lyons' paper appeared in a brand-new and hence totally obscure journal. Christakis and Fowler's work, by contrast, has appeared in some of the most prestigious medical journals in the world, including the New England Journal of Medicine and the British Medical Journal. In fact, Lyons tried submitting his article to both those places, but it was rejected without peer review. NEJM did not offer a reason; BMJ suggested his piece was better off in a "specialist journal." (Ironically, in 2010 the latter published an editorial titled "Inadequate post-publication review of medical research.") He also tried other top journals, but, according to Lyons, they were not interested because they do not publish critiques of articles they didn't originally publish. Critiques lack the same kind of novelty as original studies and they are necessarily tedious and impolite. (Indeed, Lyons' paper is not long on politeness, which probably hurt his chances.)

So is obesity contagious? What about happiness and divorce and poor sleep? One irony of the contagion battles is that even if their methods are suspect Christakis and Fowler are obviously correct that peer influence exists and that it may be even more important than we realize. As Cosma Shalizi put it on his blog last week, "there is a reason that my Pittsburgh-raised neighbors say 'yard' differently than my friends from Cambridge, and it's not the difference between drinking from the Monongahela rather than the Charles." The very idea of contagion and connectedness seems to embody the spirit of today, from the upswell of support for a young, black Chicago politician to the Facebook-driven revolutions of the Middle East.

But just because contagion is important in one context doesn't mean something like obesity spreads like a virus—much less one that can infect someone as remote from you as your son's best friend's mother. (For the record, I and my best friend's mother will eat our hats if it turns out to be true, as Christakis and Fowler claim, that loneliness is infectious, too.) Yes, we influence each other all the time, in how we talk and how we dress and what kinds of screwball videos we watch on the Internet. But careful studies of our social networks reveal what may be a more powerful and pervasive effect: We tend to form ties with the people who are most like us to begin with. The mother who blames her son's boozebag friends for his wild behavior must face up to the fact that he prefers the fast crowd in the first place. We are all connected, yes, but the way those links get made could be the most important part of the story.

TODAY IN SLATE

Politics

Don’t Worry, Obama Isn’t Sending U.S. Troops to Fight ISIS

But the next president might. 

The Extraordinary Amicus Brief That Attempts to Explain the Wu-Tang Clan to the Supreme Court Justices

Amazon Is Officially a Gadget Company. Here Are Its Six New Devices.

The Human Need to Find Connections in Everything

It’s the source of creativity and delusions. It can harm us more than it helps us.

How Much Should You Loathe NFL Commissioner Roger Goodell?

Here are the facts.

Altered State

The Plight of the Pre-Legalization Marijuana Offender

What should happen to weed users and dealers busted before the stuff was legal?

Surprise! The Women Hired to Fix the NFL Think the NFL Is Just Great.

You Shouldn’t Spank Anyone but Your Consensual Sex Partner

Moneybox
Sept. 17 2014 5:10 PM The Most Awkward Scenario in Which a Man Can Hold a Door for a Woman
  News & Politics
Altered State
Sept. 17 2014 11:51 PM The Plight of the Pre-Legalization Marijuana Offender What should happen to weed users and dealers busted before the stuff was legal?
  Business
Business Insider
Sept. 17 2014 1:36 PM Nate Silver Versus Princeton Professor: Who Has the Right Models?
  Life
Outward
Sept. 17 2014 6:53 PM LGBTQ Luminaries Honored With MacArthur “Genius” Fellowships
  Double X
The XX Factor
Sept. 17 2014 6:14 PM Today in Gender Gaps: Biking
  Slate Plus
Slate Fare
Sept. 17 2014 9:37 AM Is Slate Too Liberal?  A members-only open thread.
  Arts
Brow Beat
Sept. 17 2014 8:25 PM A New Song and Music Video From Angel Olsen, Indie’s Next Big Thing
  Technology
Future Tense
Sept. 17 2014 9:00 PM Amazon Is Now a Gadget Company
  Health & Science
Medical Examiner
Sept. 17 2014 11:48 PM Spanking Is Great for Sex Which is why it’s grotesque for parenting.
  Sports
Sports Nut
Sept. 17 2014 3:51 PM NFL Jerk Watch: Roger Goodell How much should you loathe the pro football commissioner?