Why are my children so different from each other?

Children in the same family can sometimes be strikingly different. Parents may believe they’re raising their children in similar ways, yet the children have very different personalities, abilities, and interests. Why?

Naturally, heredity plays a major role in determining temperament and abilities. One child in a family may be easygoing by nature, another more sensitive. One may have athletic ability, while another is intellectually inclined.

Gender affects personality differences as well. Boys and girls frequently have different interests and activity levels, although each may become strongly involved in activities stereo-typically associated with the opposite sex. In addition, kids often imitate what they see, and if parents have very different interests and personalities, one child may imitate her mother, while the other follows her father.

The way parents treat their children has a major impact on the development of personality, interests, and abilities. Parents shape and steer their child in many ways, both consciously and unconsciously. They may encourage musical talent while ignoring mechanical ability; they may inadvertently stifle creativity or individuality while urging their child to “be good.” They may offer her nurturing role models or help her become a leader.

Within a family, each child’s experience is unique. For instance, a firstborn receives a lot of attention during her years as the only child. However, because her parents are inexperienced, they may be cautious, demanding, and nervous at the same time that they’re loving and proud. Parents are sometimes a little more relaxed or lenient with their younger children.

There are other circumstances that lead parents to treat their children differently, often with negative results. One child may have a temperamental characteristic that unhappily reminds her parents of something in themselves or another relative. Parents don’t like seeing familiar negative characteristics reflected in their child and may wish—or pressure—her to be different.

The resemblance can be something specific. A parent with a strong temper may single out a child with a similar personality. “Your loud mouth will get you in trouble.” The parent who has negative feelings about himself may treat the child who is like him more harshly than he treats his other children.

The resemblance can also be general. A child might simply be a reminder to her parents that they (and she) are not as aggressive, talented, or intelligent as they would like to be. One parent, talking to his spouse about their child, said, “She’s stubborn, just like you.”

If one child physically resembles a parent or other relative in a way that makes parents uncomfortable, they may voice their displeasure. “Your hair is so thin, just like my sister’s.” “You have ears like your mother.” “You’re short like me.” More often parents don’t mention their feelings aloud, yet still may be bothered by aspects of their child’s appearance.

The child who is the unfortunate target of such comments will feel unhappy and singled out among her siblings. If she hears these messages often enough, she’ll internalize them. “I’m not smart.” “I’m not pretty.” “I’m not good at sports.” She may behave as though what she’s heard is true. Her siblings who have escaped their parents’ criticism will not have such negative self-images.

Siblings may also develop strong differences if one seems to be favored by her parents. For example, if parents believe one child is prettier than the other and express that belief to both, one will grow up feeling worthwhile, while the other will feel less valued and less attractive.

Sometimes parents focus too much attention, time, or money on one child; this can have a negative impact on the other children in the family. If a child sees her brother receive attention and praise for his athletic ability, she’ll look for a way to get attention for herself. She may try to compete with him, but that’s unlikely if she feels she can’t match him. Rather than risk having her parents compare her performance to his, she may eventually give up on sports altogether.

Instead, she’ll try to find another way to distinguish herself. She may try art or dancing, or develop a charming or funny manner. However, if she can’t get enough positive attention from her parents, she might seek negative attention, perhaps developing a behavioral problem at home and school. As time goes on, the unhappier she becomes, the more likely she is to become careless with her schoolwork, family, and peers, and the less likely she’ll be to get positive feedback from her parents. Her experience will be very different from her sibling’s.

Parents sometimes deliberately steer their kids in different directions, often to avoid possible conflicts and competition. If an older child enrolls in dance class, her parents may discourage her younger sibling from doing the same for fear one will outshine the other. Some parents were raised in competitive households and want to spare their children the experience of failing to measure up to a sibling. However, when parents keep one child from pursuing her interest, they rob her of a chance for enjoyment and accomplishment.

Siblings can successfully participate in the same activities as long as their parents don’t focus on competition between them or praise one and not the other. Even if one is better, there will always be something good to say about each. Both should be encouraged.