Birth order has a powerful effect on children's emotional development, on their self-esteem, and on their sense of well-being. The youngest child, the firstborn, the middleborn, twins, and the only child all have specific birth order issues that, if not atted to early on, can impair their functioning and their interpersonal relations at home and at school, and can follow them into adulthood. Parental birth order, too, plays an important role, as do...