A 2 year old requires their parental figures for their basic care such as food, water, shelter. They also need/require love, affection and a safe environment. One can determine whether or not the child in this age group is comfortable by whether or not they seem withdrawn, happy, etc.
A 7 year old is able to ask questions, communicate and demonstrate by their mannerisms and behaviors how they feel, even if they don’t directly express it. For example, if the child does not directly state that he/she is sad, he/she may demonstrate this behavior by becoming withdrawn and becoming less of themselves.
A 15 year old is also capable of demonstrating their behaviors in similar ways as a 7 year old. Perhaps they are more advanced due to their age, education and better ability to communicate; however, teenagers in this age group may become rebellious and “act out” more.