<unk>  (or impulsiveness) is a type of human behavior characterized by the inclination of an individual to act on impulse rather than thought. Although part of the normal behavior,<unk>  also plays a role in many mental illnesses.
As a personality trait,<unk>  is part of normal behavior as it contributes to adaptive functioning. However, psychological research has questioned<unk>  as a unitary psychological construct. Some authors have proposed a 3-factor model according to which<unk>  can be decomposed as a combination of attentional ("getting easily bored"), motor ("going into action") and cognitive ("inability to plan") factors. Recent theories have further decomposed<unk>  into 4 dimensions which partially map onto the five-factor model of personality:
Urgency, the feeling of negative affects for resisting the urge, is linked to neuroticism
Lack of premeditation, the inability to anticipate consequences, is linked to conscientiousness
Lack of perseverance, the inability to stick to one's task, is also linked to conscientiousness
Sensation-seeking, the experience positive feelings towards risky actions, is linked to extroversion
Increased impulsiveness is at the center of impulse control disorders such as obsessive-compulsive disorder. It may be linked to other psychopathological conditions like  addiction, ADHD, bulimia, and borderline personality.
Recent evidence from neurobiological research seems to support these psychological theories as it has been shown that these different aspects of<unk>  can be independently manipulated by specific drugs.
Impulsivity
Hysteresivity
Schizotypy
Adaptive behavior
Impaction
Agrammatism
Pronunciation
Passive-aggressive behavior