Someone I know well often tells her child she is "naughty". Whe I spoke to the little girl the other day the first thing she said was "I'm naughty". I too thought this was rather sad and replied that I thought she might have done something naughty but that she was usually a very good little girl. As a young mum, though, it didn't occur to me that regularly telling my daughter she was "naughty" would be counter-productive. I think it would be so useful for all parents (not just those deemed to be "problem parents") to have access to, and encouraged to attend, sessions that include the rudiments of child psychology.
As to the point about giving lots of praise all the time, I thought this was a fairly good idea too (and tended to do it myself) until I read an article a couple of weeks ago. The writer said that to praise a child all the time by telling him/her that they're "clever", that their work is "brilliant", etc., is not necessarily the best thing to do. He based it on evidence obtained from research. A child interprets this use of the word "clever" as a personal quality that's not connected to its own actions. So, if a child subsequently doesn't do well in a task, it becomes disheartened and questions the original statement that it is " clever", replacing it with "Now I'm not clever". If, on the other hand, someone says something like "That's a good picture - I can see you've tried very hard", they associate the outcome with the fact that they have tried/worked hard, and, if they subsequently fail, they don't become disheartened and are therefore much more self-motivating and persistent.
The writer also said that to keep heaping praise on a child for fairly average achievements devalues that praise. He talked about watching how a successful, experienced teacher interacted with children - she made insightful comments about what they were doing and listened carefully to their responses. He gave an example of a child presenting a painting to her that he'd finished. Instead of saying "Oh, that's brilliant" she looked at the painting carefully, paused for a moment and then said "There's a lot of blue in your painting" (it was all blue) and the child then decided to paint in more details.
I don't know if other gransnetters agree with this, but it seemed to make a lot of sense to me.