When two women are eating together, one is more likely to put food in her mouth when the other one is doing so too – while one’s food-filled fork is coming towards her mouth, the other one is more likely to do the same within five seconds, researchers from Radboud University Nijmegen, the Netherlands, reported in PLoS One (The Public Library of Science 1). Behavioral mimicry, the authors suggest, occurs unwittingly during a meal.

Roel Hermans, PhD., and team explained that prior studies had demonstrated that females tend to consume more food when their dining companion eats a lot, and also eat less when the companion eats frugally. Even though researchers had suggested that behavioral mimicry exists during meals, this hypothesis had never been tested and proven.

Dr. Hermans and team gathered data on 140 young adult females, average age 21 years. 70 pairs of young women dined together in a replica bar lab, which looked just like the one at the university.

In each pair of diners – one of them had been previously told to eat – the following six options were possible:

  • small portion – eat small, medium or large amount of it
  • medium portion – eat small, medium or large amount of it
  • large portion – eat small, medium or large amount of it

The other woman (of the pair) was not told anything regarding how much she should eat.

If a partner took a bite within five seconds of the other person, this was classed as mimicry. 3,888 bites were taken throughout the study. In each meal, those who were told how to eat took 30 mouthfuls (bites), while their partner took approximately 41.

The researchers discovered that females do mimic each other when eating. The non-instructed female was considerably more likely to take a bite herself within five seconds of the other one doing so. Although there was some mimicking done by the instructed eaters, the unwitting ones mimicked much more (three times more).

They added that a woman’s BMI (body mass index) appeared to have no impact on the likelihood of mimicry during the meal. However, the authors emphasized that the majority of their participants had BMIs of between 20 and 25 (normal body weight).

The authors concluded:

“The current study showed that people adjust their eating pattern to that of others. As long as such important influences on intake are not wholeheartedly acknowledged, it will be difficult to make healthy food choices and maintain a healthy diet, especially in eating contexts in which people are often exposed to the eating behavior of others.”

Written by Christian Nordqvist