Researchers quizzed 571 people aged 17 to 25 about their lives and found those who grew up with sisters were more likely to be happy and balanced.–BBC News

Well, at least “Sisters appear to encourage more open communication and cohesion in families.” The words “make people happy” only appear in the headline.

From another point of view, the researchers learned that
brothers make people sad. Or rather, “Boys tend to internalise problems and in families where there
are lots of sons, I can see that can cause problems,” which doesn’t fit nicely in a news headline.