Experts Say Your Siblings Play A Huge Role In Shaping Your Personality & Here's How

In seventh grade, I was asked to compile a soundtrack of my life thus far. While I may not remember all of the songs I chose to represent the first 13 years of my existence (plenty of angsty titles, I'm sure), I do recall defining myself as a mixtape comprised of beats I’d been introduced to by my siblings. Thanks to my sisters, I know every lyric that New Kids On The Block has ever written, and my appreciation for Linkin Park classics comes from car rides with my brother. Of course, how siblings affect your personality, or you know, your taste in music, will heavily depend on your relationship with them, but even if you aren’t particularly close, brothers and sisters seem to make an impact on your life in one way or another.

I guess it all comes back to the whole nature-versus-nurture debate, because while there’s no denying your genetics play a huge role in who you are, Darby Fox, a child and adolescent behavioral therapist, tells Elite Daily it can be "hard to separate what is genetic and what is a response to the familial environment.” In other words, it's tricky to determine which character traits you were born with, and which ones you picked up on from the behaviors of the people around you, including your siblings.

Take my second-oldest sister, for example. She's super sassy, and I’ve got a little of that myself, but who’s to say I didn’t come out of the womb sporting some 'tude? It’s certainly possible, but it’s also likely that, growing up, I mimicked my sister enough to the point where, what was once her own unique personality trait, became a part of my own persona.

Your personality is the sum of a combination of traits: some of which you're born with, and some you pick up along the way from the people around you.

Overall, science is still undecided over whether who you are is wholly a result of nature or nurture. But, from what I understand, humans are, for the most part, a product of both. Comparisons between siblings have played a huge role in these types of personality studies, and according to Psychology Today, early research in this area specifically analyzed the similarities and differences between fraternal twins, who share 50 percent of their genes, and identical twins, who share 100 percent. In terms of personality traits, the outlet reports that a little less than half of identical twins’ quirks were usually found to be hereditary across the board in these studies, compared to only about 20 percent of the fraternal twins' personas.

But what about siblings who weren't born minutes apart? How do they factor into all of this? According to Fox, the way it usually works is the younger sibling looks up to the older sibling, and is "inclined to adopt their siblings traits if they admire them." However, the therapist adds, older siblings can learn a thing or two from their younger brother or sister, too. It's really more about how you relate to your sibling, than it is about birth order.

So yes, it's definitely possible that your siblings have helped shape your personality. But what sorts of traits are most likely to stick with you in the long run?

According to Robert Glatter, M.D., an assistant professor of emergency medicine at Lenox Hill Hospital, Northwell Health, siblings' personalities can rub off on each other in three very specific ways: how you express emotion, how you act in social situations, and your eating habits. You'll likely pick up on these types of habits early on in life, but it's during the teen years, Glatter says, that you'll either decide to adopt, or ultimately reject these behaviors.

In terms of how you express emotions, Glatter tells Elite Daily it's not uncommon for siblings to "model and learn" each other's ways of communicating complicated emotions, like anger and aggression, and even more positive emotions like happiness and pleasure. "At the same time," he adds, "we learn how to gauge reactions, and when to show restraint — especially in tense or emotional situations." In other words, if your older brother is a hot-head, or your older sister is open about crying, then you might just find that you express yourself in very similar, if not the exact same ways when your emotions run high.

Now, with emotional understanding comes social understanding, and as far as Glatter is concerned, your siblings can play a huge role in both how you view a relationship, and how you communicate with the other person, whether the connection is platonic, familial, or romantic. "We often adopt patterns of socialization from our older siblings, including telephone etiquette, group interactions, as well as how we interact with our parents and relatives," Glatter tells Elite Daily. "This includes physical aspects of socialization and affection, such as hugging, kissing, and how we greet others around us on a daily basis."

And when Glatter says your siblings can influence your social habits, he means it, even when it comes to the smallest details — like how you eat, for instance. Seriously, even though you may not have even consciously realized it until now, it's likely that your older sister's disgust toward cooked carrots, or your brother's obsession with making stacks of Belgian waffles on the weekends, have shaped your taste buds in one way or another, too. Glatter says these little things, like your tastes for certain foods, often come from your sibling's example.

Birth order, on the other hand, isn't necessarily the end-all-be-all in shaping your personality, but it does play a role, at least to some extent.

It's actually fascinating just how much your birth order affects your own personality, and how that all factors into the character traits that you might end up passing along to your siblings. For example, my oldest sister April is honestly the literal embodiment of Darby Fox's definition of a typical, eldest-child personality: "the most serious and prone to controlling their younger siblings." Fox couldn't be more on-point: My sister is a super serious person when it comes to pretty much everything in life, especially work, and she's always kind of played that third-parent role in my family, particularly since we're 13 years apart.

As for middle siblings, unlike the eldest of the bunch, Fox says those who fall smack-dab in the middle are "usually less intense as a reaction to their very serious older sibling," and are "more likely to beat to their own drummer." In families where there are two or more "middles," though, Fox says they're likely to "form a strong bond," and share more similarities in their mannerisms than with any other siblings. "They observe the other siblings," the therapist tells Elite Daily, "but they don't necessarily aspire to act like [them]."

But if you're the baby of the siblings (like me), then Fox says you probably have the upper hand in your family dynamic. "The youngest are in a good position to pick and choose traits from all the older siblings," she tells Elite Daily, and that's because they've had a chance to observe, over time, all the positive and negative aspects of their siblings' personalities. "Contrary to the common belief that the youngest will be spoiled, we frequently see the youngest develop empathy, responsibility, and yet a more relaxed, forgiving personality, because they have observed their older siblings' struggles. They definitely have a vantage point."

I can vouch from personal experience that siblings can definitely play a role in how your personality is shaped. Whether you're the best of friends or polar opposites, the people you grew up with showed you how to act, what to eat, what not to eat, how to dress, and everything in between. Whether or not you've chosen to adopt these traits is up to you, but even if you made a point your whole life to reject your siblings' behaviors, they still technically offered up an example of something you didn't want to be. So really, either way, you're connected — maybe take a moment and thank them for that guidance.