Studies have shown that having a sister makes you happier and more optimistic. Hurrah for sisterhood!

 â??If you don’t understand how a woman could both love her sister dearly and want to wring her neck at the same time, then you were probably an only child.â? ~ Linda Sunshine

She wears your clothes, uses your makeup, drives you insane, critiques your life, and yet sheâ??s still the first person you phone when you have a crisis: Your sister! Built-in-friend, worst critic, psychologist and fashion advisor, partner in crime and rival – the role of a sister is a varied and interesting one.

Who else would defend you relentlessly while angry with you about something else?

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The history of psychology is scarred with false stereotypes about the sexes. Women are too competitive, other women donâ??t like each other, the list is endless.

Relationships among sisters, however, have remained exempt from such theories and are what some researchers say can be a source of happiness and self-confidence in adulthood.

Shiny, happy, well-adjusted people

A study released by Brigham Young University reported that children, both boys and girls raised with a sister, were less prone to have feelings of loneliness, guilt, fear and self-consciousness. Children with sisters were also less likely to be depressed.

In August 2009, the University of Ulster in the United Kingdom found similar outcomes to the Brigham Young study. After questioning 571 adults ages 17 to 25, they found that girls who had sisters tended to be more independent and have higher scores in school.

The study also found that sisters encouraged each other to communicate their emotions more effectively. They were found to be better at coping with setbacks and more highly motivated than those who grew up with just brothers. They also had more friends and a better social life.

Growing up with at least one girl in the family also makes people more able to cope with their problems, according to the study.

Emotional expression

Psychologists have long believed that “emotional expression” at times of upheaval is fundamental to good psychological health. Interestingly, the impact of female siblings when parents split up encourages less distress in broken homes.

It seems their natural inclination was to express themselves and encourage other family members to do so as well.

Familial ties

Sisters tie loved ones closer together and encourage them to communicate their emotions more effectively, the researchers believe.

Professor Tony Cassidy states: â??Sisters appear to encourage more open communication and cohesion in families. However, brothers seem to have the alternative effect. Emotional expression is fundamental to good psychological health and having sisters promotes this in families.â? The strength of these bonds is what memories are built on.

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Perhaps Deborah Moggach says it best: â??You keep your past by having sisters. As you get older, they’re the only ones who don’t get bored if you talk about your memories.â?

I have a younger sister. We fight, we patch up. We laugh at jokes that no one can understand. We say the meanest things to each other. Weâ??ve defended each other when others won’t. We did some of the silliest things together and there are so many stories to be recalled when we are together.

And when weâ??re angry we put up a Cold War Russia would be envious of. Yet through it all, the ice will eventually thaw and melt away and we’re right back to where we started.