PROBLEMThis study is concerned, in general, with behavioral control and particularly with behavior commonly referred to as "impulsive". The object of this study is the clarification of the concept "impulsivity" with specific emphasis upon a delineation of the kinds of behavior which might underlie behavior regarded as impulsive. To describe the impulsive person as one given to sudden, imprudent and predominately affective action agrees essentially with an authoritative psychological dictionary (6) and with other published psychological and psychiatric definitions.Thurstone ( l a ) has published a scale designed t o measure "impulsivity." derived through a factor analysis of existing scales. Thurstone describes the impulsive person as "happy-go-lucky", "daredevil", and "carefree". The impulsive person acts on the "spur-of-the-moment", enjoys competition and changes easily from one task to another. Goldman-Eisler ( 6 . P . n7) developed a self-rating schedule for impulsivity. She describes a person given t o "impulsion" as: "tending to act quickly and without reflection; as making intuitive or emotional decisions and displaying an inability t o inhibit an impulse."Though this writer has been unable t o find any studies which aim directly a t the investigation of impulsivity, there has been a good deal of writing done in the general area. The psychoanalytically oriented writings of Schilder (la) and Rapaport ( 9 s lo) on thought processes contain discussions concerning the basis of behavioral control, concurring for the most part with those of Freud(3* 4 , in his formulation of the "primary" and "secondary" processes. Of pertinence, in relation to impulsivity, are studies dealing with the development, within the individual, of the capacity t o delay reaction. Other authors introduce alternative terms for "impulsivity" which are not clearly differentiated from that term. Rapaport@) does not seem t o make any distinction between the concepts "impulsivity" and "lability". Rorschach literature abounds with references to impulsive behavior and how it is measured by the Rorschach, although little more than a brief description can be found when a comprehensive definition of impulsivity is sought.Red1 and Wineman (11) in their discussion of the "control system" describe how behavior, which would charact.eristically be imputed to be impulsive, might stem from different behavioral reactions. I n general, the literature indicates that impulsive behavior is regarded as a more or less unitary sort of behavior which is similar in all those instances in which it appears. It is probable, however, that impulsive behavior is composed of several distinctive behavioral characteristics. Our hypothesis is that tests which measure aspects of behavioral control characterist,ically representative of "impulsivity", as currently defined, upon statistical analysis will reveal the operation of more than one factor underlying such behavior assuming that in a group testing situation, a sound estimate of various aspects of behavioral control can b...