Hi, when I was doing the development charts I was just asked to provide the patterns of development for each age group. The development areas I was asked to look at where:
Physical development
Communication and intellectual development
Social, emotional and behavioural development
So I don't know why you have been asked to look at behavioural development seperately
. It might be worth googling the information as this is what I done for the development charts and found alot of useful information by doing this.