Children misbehave, do poorly in school, do drugs and search for love (sex) outside the family when parents lapse into doing their imitation of communication. When real/genuine communication takes place there is an experience of mutual satisfaction and love upon completion.
Children are integrity meters. A child can instantly tell when their parents are not communicating openly and honestly with each other, when one is withholding a thought from the other, specifically, when there's a breakdown in communication. A thought withheld serves as a barrier to the experience of love; the concept of love is there but there is no experience of it.
When the integrity of a family is out, when both parents are withholding thoughts from each other, children experience confusion. Their very growth-compass starts to wander. When one parent decides to withhold a thought from his/her partner the thought floats around in the space between the parents and the child. The relationships went from being in-integrity to being out-integrity (something is missing or something has been added to the space). The experiential love that was has become conceptualized (understood/known to be but not experienced).
Life for a child is a series of interactions, each exchange is experienced as being complete when everything feels good, or is back to normal, (hugs, kisses, and laughter). When parents argue and don’t go through to completion, the interaction serves as a barrier to the experience of integrity (of being whole and complete). There’s something different about the expressions of love thereafter.
Most often the cause of the out-integrity was a make-wrong, a condescending remark, or a non-verbally delivered stink-eye. i.e. “Where the hell were you?” “Boy that was stupid.” “I told you not to buy those . . . ” If an abuse is not acknowledged* through to mutual satisfaction then the incident remains as an incomplete, most often for life.
The foremost barrier to communication mastery with one's spouse and children is arrogance; the belief, I can do it myself, without communication-skills coaching, drives most children to misbehave and eventually do drugs. Children search for the high and the experience of love that once came from communications with their parents. The parents are stuck honestly believing they are in communication with each other and their child—yet the majority train their teen to deceive them, to con their date into deceiving both sets of parents so as to have sex.
* "acknowledged" For example: "I get that I was abusive earlier today, that it didn't feel good, when I yelled at you." Notice that no apology is necessary or required.
BTW: I know of no college/university that offers communication mastery courses to its education majors.