I agree that communication is a learned behavior.Many people may afraid of speak to other people,but that's not the way of learning." Speak your mind,even your voice is shake." That is what we should do all the time.If people don't share,all of them will confine in a small area of knowledge.That's why teachers encouraged group work and presentatiom.Another example,if you have a very good idea,but you don't share to your group because you afraid.Finally one day you will feel regretful.Due to above reasons,communicate is a learned behavior.It determine your grade and knoeledge.