This study investigates the effects of peer and sibling influence on the cookie intake of normal-weight children. A total of 44 children (24 girls and 20 boys) aged 5-11 participated in this study. Children played a sorting task while being exposed to a large amount of cookies. Children were tested alone or with an unfamiliar peer or with a sibling. Results indicated that the social condition was related to the participants' energy intake. Children eating with their siblings ate more cookies than did children eating with strangers and also consumed more cookies than did children eating alone. This pattern of results is consistent with previous research in adults indicating that familiarity between co-eaters influence how much one choose to eat. Furthermore, the degree of intake matching was extremely high among strangers, but low and not statistically significant in dyads of siblings. We conclude that matching effect is not ubiquitous and that familiarity affects the level of matching of eating in children.