The beliefs which people have about themselves about other people and about the world are habits of mind. There are many positive habits and negative habits of mind.
The difference between positive and negative habits of mind is that Positive Habits of the Mind are true, sensible and helpful whereas the negative Habits of the Mind are not true means they are not based on fact, not helpful in any way and not sensible or logical.
For example if you trust on yourself and think that you can do it, it a positive habit and if you think that you are a total failure and you cannot do anything and think negatively, this is negative habit of mind.