8 Cool Things You Didn't Know About Sibling Relationships

04/10/2015 01:19 pm ET | Updated Apr 10, 2015

Today is National Siblings Day -- the holiday celebrates the oh-so-important brothers and sisters in our lives.

"Just like Mother's Day and Father's Day have become hugely popular in our culture, National Siblings Day fills a void in acknowledging these other important family relationships," Montclair State University Family and Child Studies professor Dr. Jonathan Caspi told The Huffington Post, adding, "And recent research about siblings and their dynamics is beginning to receive attention."

Drawing from that research, here are 8 things to know about siblings and the important roles they play in each other's lives.

1. Siblings may have the greatest influence on who we are and who we become.

According to a growing body of research, siblings may be more influential shapers than parents. Why? “Sibling relationships are intense relationships involving support, love, competition and conflict," Caspi explains. "Like it or not, so much of the way we learn to handle relationships, closeness, competition, give support, argue, resolve conflicts and play we learned from our interactions with our siblings.”

2. Conflicts with parents can make sibling relationships stronger.

"When your parents, who are the anchors you’re counting on the most, are falling down on the job, siblings look to each other and find ways to pull together, because the last thing you can afford to see fractured at that point is the unit among yourselves," The Sibling Effect author Jeffrey Kluger told Salon.

3. There is nothing like sibling support.

Recent research suggests just how important sibling support is for bolstering resilience and coping with difficult life experiences. “A good sibling relationship is excellent medicine for dealing with the terrible things in life,” says Caspi.

4. Older siblings can make you smarter.

Researchers at the University of Toronto gave siblings a vocabulary test and found that children whose older siblings scored higher on the test tended to also score higher than those whose older brother or sister scored lower.

5. The more siblings you have, the less likely you are to divorce as an adult.

A study by Ohio State University found that each additional sibling (up to about seven) reduces a person's likelihood of divorce by about 2 percent. "More siblings means more experience dealing with others, and that seems to provide additional help in dealing with a marriage relationship as an adult,” said study co-author Donna Bobbitt-Zeher.

6. Firstborn girls have a decided advantage when it comes to birth order.

According to Caspi, the advantage really may go to firstborn girls, not firstborn males as many might believe. “Recent research suggests that firstborn females report having higher educational aspirations and have higher educational attainment than their siblings regardless of their sex or birth order position,” he says.

7. Youngest children tend to be more rebellious.

A study of 390 families at Leiden University in the Netherlands indicated that youngest children were generally "more rebellious and aggressive" than their older siblings. "That’s probably because they feel the need to stand up to their brother or sister to get attention from their parents," said researcher Sheila van Berkel.

8. Oldest siblings are more likely to have food allergies.

Food allergies are more common in firstborn studies, a Shiga Medical Center for Children study found. According to surveys of over 13,000 children ages 7 to 15, older siblings may be more likely to suffer from food allergies and conjunctivitis, though birth order does not seem to impact susceptibility to asthma or atopic dermatitis.

Also on HuffPost:

Lessons Kids Learn From Pets
Suggest a correction