Praising a child usually involves passing judgement on him or something he's done, albeit favorable, usually in order to manipulate him into repeating a desired action. It creates expectations in the child's mind that he may not always be able to live up to. He may wonder if we still accept and think well of him when he tries his hardest, but we don't praise him because we can't pass a favorable judgement without stretching the truth. It awakens vanity and narcissism in him because it directs his focus away from doing the act to getting the praise. It creates anxiety ("What will they think of me if I ever fail in the future?"), invites dependence ("I'm not good unless you say I'm good.") and evokes defensiveness ("I'm not the most wonderful child in the world. Last week I wanted to push Johnny down the stairs."). It violates trust in the relationship in the same way punishment does, because it leads him to believe that we don't think him capable of doing good things without being coerced with rewards. It can also rob him of the opportunity to store up riches in Heaven. True praise is due to God, alone.
However the human brain needs feedback to survive--the brain without feedback is like the man who cannot see, hear, feel, smell or taste--senseless. High-quality feedback speaks to the child's efforts and accomplishments rather than his character and personality. It's saying, "This place was a mess before you cleaned it. I didn't think it could be picked up in such a short time. This was a really hard job you did, and I can see by the smile on your face how proud you are. Thank you!" (Harmful praise would have said, "You are such a wonderful child and such a skilled housekeeper. I am so proud of you!")
There are a few criteria for high-quality feedback:
Generally, the more often children receive feedback, the better; the more specific the feedback, the better; the more immediate the feedback, the better; and the more we notice and the less we judge, the better. High-quality feedback encourages a child to continue his efforts. From our feedback, he is able to judge for himself how close he is getting to he mark he has set for himself.
Evaluative praise, on the other hand, can actually be discouraging to a child. Sometimes what we say translates in the mind of the child into something we really didn't mean. For example, after a child hits a homerun in baseball and we say, "You're great! You have a perfect swing. You should be in the Majors!" the child is likely to think to himself, "They think I'm so great, but that was just luck. I didn't even have my eyes open! That may be the only homerun I hit all season. If I never make it to bat again, they'll never know I'm really not such a great ball player anyway. I wish I never hit the homerun at all." It would have been more encouraging for the parents to simply say, "You connected with that ball and sent it sailing right over the fence. I can see how excited you are to have scored for your team." This would likely have translated in the child's mind into, "They were paying attention to me. They like to watch me play ball. I'm valuable to my team."
When we notice our children, simply by saying what we see and how we feel about it, we are showing them a reflection of the beauty that they are without making them feel self-conscious. By noticing, rather than praising, we are acknowledging that we cannot presume to know the wonders God is working in them, only that we see that He is working wonders in them and that we like what we see. We model humility by this acknowledgement, and in so doing begin to sew this virtue in our children's hearts as well.