This week, I heard a story on NPR about several recent studies on the impact that older siblings have on younger siblings that got me reflecting. Siblings can be our oldest friends. They hold our past, and we hold theirs. We may be a good fit, but we might not be. We didn't pick them out. We compete as children for time, attention, and parental resources. Brothers and sisters help form our identity, for better or worse.

The NPR story featured interviews with an OB/GYN who works with pregnant teens, who noticed a pattern that if they were helping a pregnant teen with medical needs during her pregnancy, they were very often seeing her younger sister(s) in the coming years with a teen pregnancy of their own. In a follow-up study, they showed that girls with an older sister who got pregnant as a teen are 5 times as likely to have a teen pregnancy themselves.

Another study quoted in the NPR story followed the substantial increase in smoking if another sibling smokes. It's enough to make you wonder how your siblings can impact your life, your choices, and your personality. Perhaps siblings can influence us for good (as in being responsible, getting good grades, etc.), or for bad (smoking ,drugs, alcohol, shoplifting, early sexual activity). In some families, I see children working hard at differentiating from older siblings to be different on purpose.

Birth order also comes into play. Are you a typical oldest child who is responsible, seeks to please parents, and tries to influence younger siblings? Are you a middle child who got lost in the shuffle and can get along with anybody? Are you a typical youngest who was babied a little?

As a family therapist, I sometimes feel having siblings gives us our first opportunity to learn how to have a voice, assert ourselves, and learn how to become socially skilled in working things out with other people.

Siblings can be extremely different, or amazingly similar. Sometimes all you have in common is your parents, and growing up together. Different siblings can also have markedly different childhoods growing up in the same family. Growing up you may each be competing for a niche in the family. Parents will play into this, as in "Mary is our athlete." As parents, we want to be sure to see each child in a complete way, and not stereotype their strengths or roles. You can have as many 'good children' in the family as you have children. Try not to play favorites.

With adult siblings, an attitude of tolerance is helpful, and trying to stay out of judgment. Lowering our expectations also helps. It's wonderful if they end up becoming your closest ally and supporter, but it often doesn't happen. Try to appreciate what you can about them, respect your shared past, and set boundaries if and when you need to if you have a sibling who is destructive towards you. It can be hard when you have to work together as a team with aging parents if you aren't close.

The sibling relationship impacts many of us profoundly. It helps to define your core self. It can be a source of support, understanding, and strength, or it may be the source of sadness, hurt, and the feeling that you wish you could be closer. You can do your part to be a supportive sibling, and then some of it is up to chance, parenting, the goodness of fit between your personalities, and your ability (and theirs) to accept the differences between you. Having a sibling you feel close and connected to is a great asset, but it's a team sport that takes both you and the other person.