Only children are happier, research has shown.
Having lots of siblings can make you unhappy
A new study has found that those who complain about their siblings may have some justification as kids with more brothers and sisters have worse mental health
Research conducted on over 18,000 secondary school children in the US and China discovered that those from larger families had poorer mental health than those from small broods.
The most pronounced impact on happiness was seen in families with multiple children born less than a year apart.
Professor Doug Downey, who led the study for Ohio State University, said: "If you think of parental resources like a pie, one child means that they get all the pie.
"But when you add more siblings, each child gets fewer resources and attention from the parents, and that may have an impact on their mental health."