Impulsivity

Overview
Impulsivity (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, impulsivity also plays a role in many mental illnesses.

As a personality trait, impulsivity is part of normal behavior as it contributes to adaptive functioning. However, psychological research has questioned impulsivity as a unitary psychological construct. Some authors have proposed a 3-factor model according to which impulsivity 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 impulsivity 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 impulsivity can be independently manipulated by specific drugs.