There are numerous behaviors that can be classed as negative depending on the situation and activity, including lack of initiative, being irresponsible, aggression and playing the victim. These negative behaviors can apply to work, learning habits or even dealing with things like addiction.
Negative behaviors are something that can be changed with some effort and positive reinforcement, but it can take time and effort. People with negative behavior traits may isolate themselves, lie, assume things about themselves and others, become aggressive or often put other people's priorities before their own. These can be debilitating traits in many situations in life.