Brothers and sisters are ultimately completely different from one another, despite sharing about 50 percent of their DNA. Even identical twins can be wildly different, and they're literal carbon copies of each other — more or less. But there are some weird similarities all siblings share, no matter how dissimilar they are.
I've always thought my sister and I had so much in common because of our genetic bond, but on the whole, research points to siblings being more different than they are similar. It's intuitive to assume siblings will have very similar experiences throughout their childhoods, as they grow up in the same house with the same parents. But behavioral scientists have actually found that "there is not a single family, but rather as many disparate families as there are children to experience them," as the New York Times reported. Basically, research shows that lots of factors can make the same household feel extremely different for each child in a family, no matter how similar their childhoods may look on paper.
But whether you and your sibling are polar opposites or have been doing everything in sync since you could crawl, there are a few things you'll have in common whether you like it or not. Read on for six weird ways you're just like your sister or brother.
1. They Try To Be Different From Each Other
A study published by the Society for Research in Child Development found that siblings actively try to be different from one another, most likely as a "defense against sibling rivalry." By differentiating yourself from your brothers or sisters, you'll be less likely to be directly compared to them, so it makes sense anyone with a sibling subconsciously tries to solidify their independent identity.
2. They Have Similar Levels Of Activism
Research in Social Forces found that you're more likely to vote if your siblings vote. Your level of activism has a lot to do with the background you get from your parents, particularly your socioeconomic standing, but you and your siblings will more likely than not end up being politically engaged at similar rates. Of course, that doesn't determine which side of the aisle you each fall on.
3. Conjoined Twins Share A Sense Of Taste And Smell
As reported by The New York Times, researchers spent extensive time with conjoined twins Krista and Tatiana Hogan, who are connected at their heads, and found that the girls share senses. Because of the site of their connection, "the sensory input that one girl receives could somehow cross that bridge into the brain of the other. One girl drinks, another girl feels it." The Hogans' case is extremely rare, but their sensory responses to each other's actions indicate a world of possibility when it comes to conjoined twins.
4. Their Fingerprints Are Similar
No one can have the same fingerprints — not even identical twins — but siblings do have more similar patterns on their hands than strangers do. As Genetics Home Reference explains, "The basic size, shape, and spacing of dermatoglyphs [the scientific name for fingerprints] appear to be influenced by genetic factors," which is why siblings' prints will look more alike than non-siblings. You come from the same gene pool, so it makes sense that your genes would create similar patterns.
5. They Help Each Other Become More Empathetic
Research conducted at the University of Calgary took a look at the way siblings impact one another's sense of empathy by examining the way they react to someone in distress, and the results indicate that "both younger and older siblings positively contributed to each other's empathy over time," as Marc Jambon, postdoctoral fellow at the University of Toronto, reported to Medical Xpress. Simply having a sibling makes you more empathetic, so you can give a shout out to your parents for gifting you with a built-in kindness builder.
Regardless of how close or distant you and your siblings are, they're the people who shape your earliest experiences, allowing you to test out everything from conflict resolution to secret keeping. They're the people you share a history with, no matter what.
6. They Can Have Their Own Language
Many sibling pairs create a private form of communication, but inventing a new language is particularly common among twins. A study published in the U.S. National Library of Medicine National Institutes of Health stated that up to 40 percent of twins have an "autonomous language" they use to talk to one another privately.