Why do 24 million
people in the United States currently suffer from an eating disorder? Numerous
studies confirm that genetic factors and personality types play a role. We know
that biological influences can predispose an individual to develop a disorder,
and that perfectionism and a heightened focus on body image are common traits among
But these factors
do not tell the whole story. Social norms contribute significantly to the development
of eating disorders; more specifically, perceptions of peers’ approval have a
major influence on our behaviors.
The fact that our
friends can have a powerful influence over our behaviors comes as no surprise. One
way this happens is through the influence
of social networks. In 2007, a study in The
New England Journal of Medicine found that obesity spreads throughout
social networks, as those who have more friends who are obese are more likely
to be obese themselves. This suggests the powerful effect that friends’
behaviors can have on our own, at the cost of our health.
We tend to look
to our social environments for clues about what is socially acceptable and what
is not. We usually sort these messages into two
main categories: descriptive norms and injunctive norms. The first embodies
behaviors that people often do, such as wearing clothes in public (at least, on
most occasions). We can easily determine this norm by watching those around us.
Injunctive norms, on the other hand, require more interpretation. These norms are
more concerned with what people approve or disapprove of, which can be deduced
by stares and whispers in response to a nudist in the grocery store, for example.
injunctive norms, or the approval of our peers, end up having a greater
influence on our own actions than simply what we observe in others’ behaviors. This
pattern holds true for eating disorders.
For example, college
students who endorsed the injunctive norms of peer thinness were more likely to
have body dissatisfaction and disordered eating than those who only endorsed
the descriptive norms of peer prevalence of eating disorders, according to a
study in Eating Behaviors in 2013. In
other words, it was not what these students thought other students were doing that influenced their behavior,
but what they thought other students approved of.
Another study, published
in The Journal of Applied Social
Psychology in 2013, found that adolescents who believed their friends
approved of smoking were more likely to smoke than those who were simply aware
that their friends smoked. Again, the descriptive norm, which provides
information about friends’ behaviors, is much less accurate at predicting
future behavior than the injunctive norm, or information about what would win the approval of friends.
asking the five closest friends of each participant what they thought about
smoking, their responses revealed significant misinterpretations: Their friends
approved of smoking much less than they had perceived. This distinction is
troubling, as faulty perceptions of peer acceptance encouraged unhealthy
behavior. The same pattern could be at play for eating disorders.
This is not
purely bad news. According to these studies, our peers are actually endorsing unhealthy behaviors much less
often than we think. Also, evidence suggests that although influential, these
norms are malleable.
In 2010, researchers
from Syracuse University found that when college students were given
information about what other students at their university really thought about heavy drinking (much more disapproval
than one might assume), they were much less likely to believe that their
friends would approve of these behaviors than the students who did not receive this
information. This suggests that after presenting someone with information
regarding accurate injunctive norms, they will then shift their perception of
what they believe will elicit approval.
importantly, when participants were warned about the negative consequences of
overestimating norms about drinking, their perceptions of both descriptive and
injunctive norms decreased. This suggests that alerting people to the dangers
of misperceiving the prevalence and approval of unhealthy behaviors could
result in a decrease of these behaviors overall. Perhaps a nutritionist could
speak during college orientations, including information about both injunctive
norms and the hazard of misperception.
of genetic predisposition and environmental influence, including perceptions of
injunctive norms, proves to be a deadly one, as eating disorders have the
highest mortality rate of all mental illnesses. Increasing both the
availability of accurate peer injunctive norms and providing information about
the risk involved in misinterpretation could not only give people access to the
correct information, but could also save lives.
Claire Brown PO ’15 is a Psychology major from Washington, D.C.