My 19-month-old son has always been a good boy and has done whatever I asked him to do. Recently he started refusing to do anything I ask of him. He has started crying and hitting me even when I ask him to do simple things. Where have I gone wrong? What should I be doing differently? Will he always be like this?

Children of perfect parents (if there were such a thing!) would still need to go through the developmental phase your son is going through. Ideal children do NOT always agree with their parents. Ideal parenting does not prevent the "Terrible Twos" -- it helps children navigate them.

Although children are each born with a unique personality, their early experiences are profoundly influenced by their physical states and by their environments (primarily their parents). Thus, early on, your son's desires tended to be either responses to physical needs (he was hungry and wanted to eat, he was sleepy and wanted to sleep, or he had a soiled diaper and wanted you to change it) or reflections of your desires. He wanted things that made you happy, that engaged your attention. When you smiled, he smiled. When you became tense, he became emotionally agitated. Through that first year a wonderful dance between parent and child developed as your son mirrored your moods. Because his moods were usually in synch with yours, he seemed like a "good boy."

Gradually, though, sometime after he had mastered walking, an irresistible urge to make his own choices began to well up inside him. This is an exciting development, but the difficulty with his making an independent choice is that he must disagree with you in order for the choice to be his own. Now, when you ask him to do something, he refuses.