I feel like this answer varies. It’s all of the factors like social, emotional, economic, environmental, etc. development is a slow process but is abrupt in a child’s life because they are growing fast so everything is changing for them fast as well. And it’s even more impactful if the child has bad environment or emotional states where their development is interrupted.

I know this is one of the most important ones because cognitive skills is what allows the child to be able to properly communicate with others while also developing new life skills along the way. This is the way they think and how they decide to respond during certain situations.