It's not really news that what and how much one eats can be influenced by the social setting of the eating environment. This can be an important factor when considering how to help people who live alone (for example, elderly folks) consume enough food to maintain health. But what is needed for this social facilitation to occur? Is one other person eating at the same time sufficient? Or, does there need to be a group? A new study by Japanese investigators surprisingly found that people who eat while watching themselves in a mirror, or even just seeing a picture of themselves eating, will eat more than if they don't see either one.
Drs Ryuzaburo Nakata and Nobuyuki Kawai from Nagoya University, Japan, recruited 16 older Japanese adults (11 males) — between the age of 65-74. The participants were told they were testing different flavors of popcorn — salty or caramel-flavored. They were tested while watching themselves in a mirror, or when a monitor showing a blank wall replaced the mirror in the test room. The investigators found that in the mirror condition the test subjects ate more popcorn, and also rated the popcorn more highly than in the monitor condition; these differences were statistically significant.
In the next testing situation, the mirrors were replaced by static pictures of each participant or the monitor showing a wall as before. Twelve older Japanese adults participated in this experiment (7 men and 5 women; average age 69 years). Again, participants ate significantly more popcorn and rated it more highly when they saw a picture of themselves eating.
Finally, the investigators replicated the first experiment — with mirrors — with 16 young adults (11 men, average age 21.5 years). Again, consumption was greater when the subjects saw themselves in mirrors, and they rated the popcorn more highly in that condition as well.
So this small study suggests that so-called "social" facilitation of eating doesn't have to be very social at all. Now, these were quite small samples participating in the experiments, and the people were all Japanese, so it's not clear that the results would hold up in larger samples or within different cultural groups. However, the results are intriguing and possibly could be useful for encouraging food consumption by some individuals.
