The Science of Siblings
Quick Quiz:
Scientific research has proven that siblings can….
A) Make you thinner
B) Reduce your risk of allergies
C) Decrease your odds of divorce
D) All of the above
Answer: D, all of the above
Siblings. It’s been said if you can get along with them, you can get along with just about anyone. It’s true that relationships with brothers and sisters are the precursor to relationships outside the family unit, but groundbreaking research is confirming that sibling relationships indelibly shape our whole person. In his article “How Your Siblings Affect Your Success According to Science,” Dr. Jonathan Caspi notes this profound influence. “It is an odd thought that our sibling relationships may be at the center of what makes us who we become. We may prefer to say that our success is due to parental support, social connections and particularly our personal attributes, including our own hard work and intelligence. However, it is our siblings that may be the most influential in this regard. They shape our sense of selves, our identities, our skill sets, and ultimately our life choices. Simply put, if you had a different sibling you would be a different person.”
For years now, researchers have tried to peg what the primary influence is in shaping a person. First noted were parents (particularly mothers), then genes and, last but not least, peers, who arrive late on the scene but have lasting impact. All of these were a good start, but the scientific community had more questions than answers after all data had been excavated from theories. The missing link, it turns out, is siblings.
From birth, a sibling becomes a coconspirator in crime, best friend, arch nemesis, protector and playmate (sometimes all of the above within a few minutes’ time). We learn to fight and make up, build friendships or sever ties and even navigate the murky waters of relationships with the opposite sex, all thanks to lessons learned from a sibling. A spouse will enter the picture later in life; parents will, at some point, pass on. Siblings, then, may be the only ones to qualify as true partners in life, permanent travel companions that navigate life’s waters for the entire journey.
Perhaps one of the most critical components to this impact is time. According to a regarded Penn State University study, a child will spend more than 33 percent of his free time with his siblings—more time than will be spent with his parents, friends, teachers or even alone. The study later found that adolescents, while striving for an identity outside of the family, still devote more than 10 hours a week to time with their brother or sister (and the numbers go up, closer to 17 hours, in larger families).
It should come as no surprise, then, that familiarity breeds some contempt. Laura Kramer, professor of applied family studies at the University of Illinois Urbana-Champagne, discovered that for siblings between 3 and 7 years old, typically 3.5 squabbles ensue within an hour’s time. While a Canadian study found that children within the 2-4 age range are known to clash a terrifying 6.3 times an hour. When children learn conflict resolution skills within the permanence of a sibling relationship, they garner life skills for the classroom, workforce and beyond.
While most arguments develop over territory, parental favoritism can have its effect as well. As many as 65 percent of mothers and 70 percent of fathers exhibit a preference for one of their children. (For mothers, it is typically a firstborn son, while fathers tend to display a soft spot for the youngest daughter.) Whether a parent denies showing preferential treatment or not, studies show otherwise. Brothers and sisters pick up on this and develop a process known as de-identification, a phenomenon where siblings differentiate themselves instead of emulating one another, to avoid the risk of comparison. Parents can further complicate the dynamic by only affirming certain kinds of accomplishments, such as esteeming sports over fine arts or vice versa.
Comparisons among siblings always will exist, whether within the home or outside it. But birth order plays a large part too. Firstborns are more likely to be senators, astronauts and CEOs, many thanks to the exclusive time and resources they had with their parents before siblings came along, along with the unique mentoring relationship they have with younger brothers or sisters (an average three-point higher IQ than siblings doesn’t hurt either). Last-borns are notorious for becoming intuitive and charming. Is it any wonder that some of the world’s greatest satirists and comedians are babies in their families? Middle-borns are often thought to be neglected or perhaps struggling for attention, but research has shown that may be to their advantage by making them more independent and creative thinkers. Hallmark middle-born traits include empathy, out-of-the box thinking and sharp negotiation skills, making them leaders in their own right.
Regardless of where you fall in line in your family tree, know that you have forever been shaped by your siblings and they have forever been shaped by you. And that relationship—for better or worse—is one of the most valuable ones shared in a lifetime. As Time Magazine senior editor and author of the book The Sibling Effect Jeffrey Kluger so wisely affirms, “Having siblings and not making the most of those bonds is folly of the first order. If relationships are broken and are fixable, fix them. If they work, make them even better. Failing to do so is a little like having 1,000 acres of fertile farmland and never planting it. Think what you’re allowing to lie fallow. Life is short and it’s finite and it plays for keeps. Siblings may be among the richest harvests of the time we have here.”
Lauren Greenlee is the firstborn of four children and the mom to three sons. She writes from her Olathe home.