When women sit down to a meal together in a restaurant, they often badger each other about their choices. If one woman orders a salad, the others might tease her about "being good" or that she's thin as a rail and should eat something more. Women may also laugh when the dessert menu is presented, only willing to order something if another woman caves in first. A new research study says that these behaviors may be just the beginning of how women influence one another when eating. The research may have implications for the understanding of eating disorders, and how eating disorders tend to be clustered geographically and in social networks. The study, published in The Public Library of Science 1, was conducted by researchers at Radboud University Nimegen in the Netherlands. The researchers found that when women sit down to a meal together, one woman is likelier to take a bite if her companion takes a bite. The mimicry occurs within five seconds of one person putting a bite of food to their mouths, according to the study. The behavioral mimicry that happens during meals is all unsuspected by the participants. Led by Roel Hermans, PhD., the research team was conducting the study based on previous studies showing that females have a tendency to eat more when their eating partner also eats alot, and eats less when their partner eats sparingly. Researchers have long suspected that behavioral mimicry took place during meals, but the theory had not been backed by scientific research. The researchers recruited 140 females with an average age of 21, all in their young adult years. There were 70 pairs observed as they shared a meal in an imitation restaurant that looked the same as the one located in the university. One person, in each pair, had been instructed how to eat. Each person was given one of six options, based on meal size and how much they were told to eat. There were small, medium as well as large portions used, and the participant was instructed to eat a small, medium or large amount of that portion. The other person in each pair wasn't told anything about how much food she should consume during the meal. The researchers measured behavioral mimicry by counting how many times an uninformed participant, within five seconds of her partner, took a bite. There were a total of 3,888 bites taken during the course of the study. The informed participant ate about 30 mouthfuls, while the partner ate about 41 bites. The researchers found that though both women tended to mimic one another's eating behaviors, the women who were uninstructed mimicked three times more than those who were instructed how to eat. The information may prove useful in understanding why participation in certain groups, such as sororities where multiple meals per day may be taken together, there is clustering of eating disorder symptoms.