IMPULSIVITY. — In ordinary language, this denotes the tendency to perform, under the pressure of a sudden conscious or subconscious ideational-affective state of mind, sudden acts characterized by irrationality, inappropriateness, abruptness, and irresistibility.
Normally, the act of intellectual motor appetition, situated within the plan of a representation of finality, is sustained and expressed under the pressure of a motive, a psychological complex consisting of an idea more or less charged with affective tension. Hence the characteristics of the act of willing are modeled on those of the animating motive, whether logical or illogical, legitimate or illegitimate, proportionate or disproportionate; likewise, the impulsive act, whose determination is linked to the emergence in the subject’s mind of a sudden, often tyrannically obsessive motive, charged with affective tension, which does not arise logically from a well-ordered series of reasonable premises, is discharged tumultuously and disorderly through the psychophysiological moment (“impulse”) into the practical act.
Two further circumstances contribute to i.: one psychological, represented by the permanent or momentary emptiness of consciousness, poor in or deprived of inhibitory counter-motives, whereby the motive-idea tends automatically to become an act; the other physiological, whereby operative impulses tend to overflow their delimited channels of conduction, unleashing, in a kind of internal short circuit, a storm of emotional and motor reactions foreign or disproportionate to the plan of responses demanded by the particular circumstances of the moment. I. may manifest itself in varying degrees, from the mildest, in which the voluntary act loses, to a lesser or greater extent, its characteristics of deliberation and logical motivation, to the most serious, in which it assumes the appearance of an immediate, violent, instinctive reaction, in which the intellectual element seems entirely absent, wholly absorbed by the violence of the emotional and motor discharge. Some authors (G. H. Schneider) wish to establish close relations, even identity, between impulse and instinct, speaking of instinctive impulses that they group into “impulse-sensations,” “impulse-perceptions,” and “impulse-ideas.”
In particular, the most serious manifestations of i. epilepsy (v.), both in its disorderly forms of convulsive seizures and in its masked aspects of “equivalents,” or in sudden impulses to commit acts of violence, to set fires (pyromania), or to destroy (clastomania); alcoholism (v.); in the manic episode and in the raptus melancholicus of manic-depressive psychosis, which may culminate in the patient’s sudden suicide; and in many other forms of chronic intoxication or psychosis, such as cocaine addiction (v.), dementia (v.), paranoia (v.), mental deficiency, etc. Thus arises the medico-legal figure of the impulsive madman, capable of the most atrocious and sudden crimes, whose characteristic features are the absence of utilitarian motivation, incomprehension of and indifference to the harm caused, and lack of remorse.
The impulses of psychotics must be distinguished obsessive psychosis (v.), in which the individual suddenly has the idea of performing an action that is disagreeable to him or contrary to the intellectual or moral structure of his personality; the subject has the impression that he will be unable to resist the obsessive impulse that torments him and is so painfully experienced by his consciousness (and it is precisely in this intellectual opposition and this moral suffering that the specific difference from the impulses of the mentally ill lies). If the action that is the object of the obsessive impulse is of little importance, harmless, and without moral significance, the individual ultimately performs it, thereby regaining, at least temporarily, his peace; if the idea entails a repugnant, seriously harmful, or otherwise sinful action, this is inhibited and repressed, although the suffering of the struggle and fear of a possible future defeat remain.
I. always represents a defect in the normal course of volitional activity and, correspondingly, in the imputability of the act committed. It is not possible here to provide a general criterion of judgment, since this is linked to the characteristics of the illness producing the defect; thus one may range from the case of complete irresponsibility to that of the slightest mitigating circumstance. Reference should therefore be made to the individual entries dealing with the various chronic intoxications and psychoses capable of influencing the individual’s psychomotor activity; V. PASSIONE.