I wonder how many folks out in "Amazonland" think that childrenlike Jacob exist? He seemed like such a flat character. As a teacher I can not imagine. a Mom, stay at home, former teacher, not recognizing her son had problems. Also, one would think, since her Dad was a psychiatrist, she would have, at the very least, consulted with him.
I don't think Jacob was very realistic, if I am reading him as the author intended. What probably is true is that all parents sometimes wonder who their children are and many probably all have moments when they don't like their kids, although they love them. But Jacob seemed to me to set off too many flags such that even if you are his parents, you have to have some inkling that either he is not entirely happy or is worryingly anti-social. It's easy, of course, to say that as a reader with a full canvas. But I wonder whether someone like Jacob could fly so entirely under the radar in reality -- it's not just his parents who are missing the signs. Then again, we do hear questions like this whenever a serial killer makes himself known. How could we have missed it? All of the foregoing assumes, however, that Jacob is a bad seed, and of course, that is never proven or is clear. There is the possibility that, like many kids, he was misunderstood and in the wrong place at the wrong time.