If you think of parental resources like a pie, one child means that they get all the pie, Downey said. 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.
That teenagers fared worse when their siblings were a similar age supports the resource dilution explanation, where each additional sibling means fewer resources and attention for each child.
[
add
]
[
|
|
...
]