How does a child's individual style and temperament affect behavior?

Ans: Between age 2-6 yrs, a child goes through walking with good balance, some start running. The uprightness in posture and walking is mastered.The right brain growth is, maximum to start with around 6 yrs the left brain starts, maturing and slowly the interconnecting fibres between the right and left brain is getting matured thereby the child's school readiness is attained

Ans: Mischief, temper tandrums are the language of their expressing their Independance.Now 0-7 yrs is the maturation of the physical body majorly to get physical Independance. With this there is this experience of " I am different from the world" if at this stage, if the child already been given many choices earlier then the reason for wanting and not wanting as choices. Which brings on the reason not wanting to imitate anymore of the parents. So around 7 yrs is where one can expect this behaviour.From 7-14 yrs parents play a model of walk the talk which becomes truth for the child. So each stage of child development is a learning to the parents

Ans: Silence is a beautiful and powerful language. Communication is both by talking and by our body-language. Home is his familiar place where he knows everyone and can talk. But school he must be trying his best behaviour, working on academics and observing everything by being silent. A few suggestions:
1. Connect with a few mothers from his class, meet for fun play in the park, perhaps 2-hours with other children at home as aplay-date.
2. Make him join an activity class where his classmates are going so that he builds friendship and starts to talk.
Do write back, on the progress.