What will you share with your siblings this holiday?

For many people the holidays are a time to get together with those we know best – our families. Nobody shares more in common with one another than siblings. We grew up together, shared the same household, ate the same meals, and attended the same grade schools. I know some siblings who even dated the same boy or girl in high school. Not to mention, we happen to share a great many genes in common. With all of these similarities, we should practically be clones of one another.

So why is it that when I get together with my brothers and sisters, I feel like I’m a stranger in the room? Sure, we look kind of similar, and I recognize some of those facial expressions from staring in the mirror while shaving, but these people are really different from me! And from one another. A report on National Public Radio highlights research that is explaining the ways in which siblings are different, and in particular why these differences occur.

Historically, psychologists studied siblings in three ways: their physical characteristics, intelligence, and personalities. What they’ve found is that siblings are usually quite similar in the ways they look and in their cognitive abilities. Personality, on the other hand, is a whole different story. In fact, we have similar personality characteristics as our siblings only about 20% of the time.

So what accounts for our unique personalities? The article discusses three theories, all related to the effects of our environments. Most people think that our shared environments should make us similar to one another, but the opposite is true. Our shared environments make siblings different from one another, not alike. Even though we grow up in the same households, our individual experiences are often dramatically different. This is because we experience major events, such as divorces and deaths, differently depending on our particular ages and circumstances when these things happen. And even if our parents want to treat us the same, they don’t. In addition, there comes a time when our families and parents influence us less than our friends. We have the benefit of being able to choose our friends, and the time we spend with them and the experiences friends share with one another eventually out-weigh the impact of our families.

So when you’re exchanging gifts with your siblings this holiday season and you’re wondering why they gave you a box set of KISS CDs, and you’ve listened exclusively to classical music your whole life, maybe you’ll have a better understanding of their point of view, not to mention an interesting topic for conversation that the whole family can relate to.