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How Does Your Social Network Shape Up?

Aug 24, 2013

A study funded by the National Institute on Aging (NIA), a component of the National Institutes of Health (NIH) showed that obesity spreads within social networks despite geographical distance. According to their research, the closer the social connection the more impact family and friends made.

Here is what they found:

  • A key participant's chances of becoming obese increased by 57 percent if he or she had a close friend who became obese.
  • In same-sex friendships, a close friend becoming obese increased a key participant's chance of becoming obese by 71 percent. However, no such association was found in opposite-sex friendships.
  • The perception of friendship also was an important factor. When two people identified each other as close friends, the key participant's risk of becoming obese increased by 171 percent if his or her friend became obese. In contrast, a key participant was not likely to become obese if someone claimed a close friendship with him or her but the key participant did not report the friendship.
  • Among pairs of siblings, one's becoming obese increased the other's chance of becoming obese by 40 percent. This finding was more marked among same-sex siblings than opposite-sex siblings.
  • In married couples, one spouse's becoming obese increased the likelihood of the other spouse becoming obese by 37 percent. Husbands and wives appeared to affect each other equally.
  • Obesity spread across social ties, despite geographic distance from one person to another. Further, social distance--the degree of social separation between two people in the network--appeared to make more of a difference than geographic distance in the spread of behaviors and norms associated with obesity.
  • An immediate neighbor's becoming obese did not affect a person's risk of becoming obese.
  • Smoking behavior was not associated with the spread of obesity from person to person.

However, scientists Christakis and Fowler from a NY Times article “Are Your Friends Making You Fat?” make important mention of the two way street. “Yet there is also, the two scientists argue, something empowering about the idea that we are so entwined. ‘Even as we are being influenced by others, we can influence others… therefore the importance of taking actions that are beneficial to others is heightened. So this network thing can cut both ways, subverting our ability to have free will, but increasing, if you will, the importance of us having free will.”


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