Our eating behaviour changes to match that of the company we keep due to a subconscious mimicry response that causes us to match our dining partners bite for bite.
It’s been known for a while that the company we keep can influence our behaviour at the dinner table. People eat more when others eat more, and less when others limit their intake. Now researchers in Canada and the Netherlands think a subconscious process known as behavioural mimicry might be the reason.
Writing in the journal PLoS One, Roel Hermans from Radboud University Nijmegen in the Netherlands disguised his lab as a restaurant and set up a hidden camera to observe eating habits. 70 pairs of young women, who had not met before the study, were then invited to share a brief dinner, lasting around 20 minutes.
The researchers then counted every single bite that the women took – 3,888 in total – and recorded when they took place in order to determine how many were “mimicked bites” compared with “non-mimicked bites”. A mimicked bite was defined as one that takes place within 5 seconds of the other diner taking a bite.
Their volunteers were significantly more likely to take a “mimicked bite” than to take a bite outside that 5 second window – suggesting mimicry was playing a major role in the decision to take each bite.
Previous studies in behavioural mimicry have put forward a possible brain basis for this behaviour; perceiving an action influences the activation of a group of nerves known as mirror neurons – in this case in the motor system that would control the motions required to take a bite – and this makes the perceiver more likely to mimic the action. It’s also possible in this particular case that the diners subconsciously monitored each other’s actions in order to maintain a similar eating pattern.
As the meal went on, however, the amount of mimicry reduced. The researchers split the 20 minute dining session into two blocks of ten, and found that the women were more than three times more likely to mimic in the first half than in the second. As the women were strangers when they arrived, the researchers attribute this to a getting-to-know-you period, where mimicry is enhanced.
Understanding the behaviours that influence our food intake can help people to take more control over their diet, and be more mindful of the factors that alter how much we chose to eat. But this research can also help to find ways to curb the social influence on more damaging behaviours such as smoking and drinking alcohol.