What are the norms of physical development and why do we need them?

Question

for a 1 and 3 year old

Answer 1

Here is a website that lists some developmental milestones

http://www.childdevelopmentinfo.com/deve...

We need to know the normal course of development for children to help us detect any developmental delays that could be signs of learning disabilities, health problems, or other disabilities.  Many disabilities can be prevented or treated better with early detection.