The bonds of sisterhood may provide more than just relationship advice and friendship for the involved parties. According to a recent study by Tony Cassidy, psychology lecturer at the University of Ulster in Northern Ireland, sisters improve the emotional wellbeing of their siblings. The study, which involved roughly 600 young adults, found individuals with sisters to be significantly more optimistic and happy than those without sisters.
"We decided to investigate this area because of an incidental finding in a previous study which suggested that following family breakup, girls who had sisters showed higher levels of achievement motivation than those who had brothers," Cassidy told the Daily in an e−mail. "We believe the mechanism through which this occurs is expressiveness. In other words, girls generate a more open and expressive environment in which issues are discussed."
Freshman Elizabeth Moynihan, who has an older sister and two younger brothers, was not surprised by the study's results.
"My sister and I can talk about anything," she said.
Moynihan feels that having a sister with different interests than her own has helped define her own identity.
"It's helped me find out who I am by our differences," she said.
But those without sisters aren't necessarily out of luck, according to Cassidy.
"Having female friends, particularly in the early years, is likely to have a similar effect," he said.
In light of this finding, he said, parents should try to ensure that their toddlers have a diverse group of friends in terms of gender.
Chi Omega President Lizzie Langer agrees that female friends can fulfill the roles traditionally played by sisters, which is why she joined a sorority.
"Due to the belief system we share as members of Chi Omega, women with different backgrounds and life experiences can relate on new levels," Langer said. "I believe the term ‘sisters,' used for the members of Chi Omega and other sororities, is very appropriate."
Langer explained that living together in a house affords many sorority sisters a relationship more similar to biological sisterhood than some female friends achieve. Still, she said, sorority sisters who do not live in the house are conceptualized as sisters by the rest of the group as well.
"As I have experienced both living in and out of my sorority house, I can attest to the fact that not only does Chi Omega provide a welcoming and comfortable home for sisters who live there, but it also serves the exact same purpose for the sisters who do not," Langer said.
Cassidy believes that parents' gender expectations may be responsible for his discovery, citing examples like parents organizing their daughter's fantasy tea parties while gifting toy guns and footballs to their sons.
"Despite modernization of parenting, we still socialize boys towards more stoic behavior. Girls, on the other hand, are socialized toward more expression of emotion," Cassidy said.
An earlier study performed at Harvard Medical School in 2008 found that happiness correlated not only with having sisters but also with having siblings in general. The study, which examines the contagious nature of happiness, found that when a person is happy, his or her siblings living within a one−mile radius are 14 percent more likely to be happy than siblings living farther away. The study, which surveyed more than 5,000 people over a period of 20 years, found a high correlation between happiness and the perceived happiness of nearby friends and family.
At the same time, there is such a thing as having too many siblings, according to a study of nearly 40,000 British households by the Institute for Social and Economic Research at the University of Essex, which found that an increase in the number of siblings within a child's home correlated with a decrease in the child's happiness.
Professor of Child Development Fred Rothbaum said that the correlation between number of siblings and happiness is not as straightforward as it may seem, though.
"Statistics say that larger families tend to be poorer families, so it could be related to poverty instead of to sibling size, [or] it could be related to the amount of attention," Rothbaum said. "It might be great to have a sibling support group, but if that sibling support group is really large, that diffuses how much parents and other adults are able to give the kids."
In Rothbaum's experience, he has not found that people with siblings are always happier than people in single−child families. Still, he said, there is some validity in recognizing the potential benefits in having a sibling with whom to share childhood.
"The meta−analyses I've seen on only children do not show that they're less happy, so I'd be curious to look more closely at [the University of Ulster and Harvard Medical School] studies," Rothbaum said. "But, having said that, a sibling is a lifelong companion. We are programmed to be in groups, to belong, and if we have a sibling, there's a natural group to which we belong. I can see that to be a source of support."
