Except when they steal your clothes.
Having a sister officially makes you happier and more optimistic.
That's according to a new study by researchers from Leicester’s De Montfort University and Ulster University. They asked more than 570 people aged between 17 and 25 psychological questions about a number of different topics.
The results suggested that the people who grew up with sisters were encouraged to communicate more openly about their feelings, which also gave them a more positive outlook on life.
Professor Tony Cassidy carried out the study and told The Mirror that:
"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.
"It could be that boys have a natural tendency not to talk about things.
"With boys together it is about a conspiracy of silence not to talk. Girls tend to break that down."
He added that this study could be especially useful for families where the parents had split:
"I think these findings could be used by people offering support to families and children during distressing times. We may have to think carefully about the way we deal with families with lots of boys."
