It is so interesting to think about who is an only child because it is not that simple. Most of us have blended families. Families are so much more complicated than they used to be. You can have step siblings. You can have huge gaps in age. In the studies, if you live alone in a household with your parents for seven years, you are considered an only child in the literature. So for example, if I were to have a child and then seven years later have another child, they would both test as only children from the most part. Also, if I have an only child and then I marry someone, a second partner, who has another child and there is a seven year gap there, that would often make them an only child. And so, I take all these studies with a little grain of salt because the data can´t tell us everything about the lived experience and there are some people who experience life as an only child if they have a sibling who is five years older but goes to boarding school or who doesn´t experience life as an only child even though they are the only child of two biological parents but have really close step siblings, so it is really hard to say sometimes. And I think that we need to be a little relaxed about the definitions and how much they matter in today´s society.