The author said that the sibling relationship of young child (0-7 ages) is different between first born or second born and gender. First, the first born children act like a teacher to the second children. They teach family rule, lessons or something which they know to younger and they tend to imitate. On the other hands, the second children are more likely to play their siblings. The age gap is another cause of formatting sibling relationships. If siblings have a wide age gap, the first phenomenon has a more strong possibility to occur. Second, gender also forms sibling relationships. Girls are more likely to teach something to their siblings and boys are likely to focus play with theirs. Moreover, same-sex siblings have rival relationships than mixed-sex siblings. It is not only for biological siblings but also adopted siblings are same. Â
