There is a tendency to look at people who have put on weight
and assume that there is something about their personality that made them gain
weight. We rarely contemplate the
opposite possibility, though. Perhaps
behaviors that lead people to gain weight actually lead to changes in people’s
personality over time.
This possibility was explored in a fascinating paper by
Angelina Suttin and seven co-authors in the July, 2013 issue of Psychological Science.
These authors examined data from about 2000 people taken from two
longitudinal studies. The adults in
these studies were generally in their 40s and 50s at the time of the first
measurement. The individuals in these
studies took a basic personality inventory and also had their height and weight
measured (in one study) or they self-reported their weight (in the other). The measurements for each individual were
taken 8-10 years apart.
The researchers analyzed the data to see whether significant
weight gain (a gain of more than 10 pounds) and significant weight loss (a loss
of more than 10 pounds) influenced measures of personality. Weight loss had no reliable effect on the
measures of personality. However, weight
gain had two relationships to personality.
Participants who gained more than 10 pounds were just as
impulsive as those who did not at the baseline measure, but were significantly
more impulsive in the follow-up test than those who did not gain weight. Surprisingly, those who gained weight also
increased in how likely they were to deliberate about decisions compared to
those who did not gain weight.
This pair of findings is interesting for a number of
reasons. First, it suggests that
repeated behaviors that lead to bodily changes can ultimately influence
personality characteristics as well.
Giving in and eating too much repeatedly over a 10-year period can lead
people to become more impulsive overall.
Second, the combination of results for impulsiveness and
deliberation is interesting. You might
think that people who are impulsive do not think about their actions and the
consequences of their actions. In this case,
though, people are both more impulsive and more deliberative. That means that they likely understand the
consequences of their impulsiveness, but they cannot stop themselves from
acting.
These data suggest that it might be useful to take a
different approach to weight loss, particularly with older adults. Often, we provide a lot of information about
healthy eating and weight loss. The
assumption is that if more people understood why their eating habits are
leading to weight gain and potential bad health, they would change the way they
eat.
These data suggest that information alone is unlikely to
help. The people in this study are able
to think about their actions, they simply don’t change their behavior in the
face of temptation. That suggests that
we need to help people to change their environment to make the behaviors they
want to perform easier to do and the behaviors they want to avoid harder to
do. In addition, it suggests that people
need to engage with family and friends to save them from temptation. Ultimately, when you are likely to be
impulsive, the people around you can be a great source of strength.
