Table 1.

Definitions of Temperament Dimensions as Defined by Chess & Thomas (1996)

Dimension	Definition
Activity Level	the motor component present in a given child’s functioning and the diurnal proportion of active and inactive periods
Rhythmicity	regularity; the predictability and/or unpredictability in time of any function … such as feeding, sleeping, elimination
Approach/Withdrawal	the nature of the initial response to a new stimulus, be it a new food, a new toy, or a new person
Adaptability	responses to new or altered situations. One is not concerned with the nature of the initial responses, but rather the case with which they are modified in the desired direction
Intensity of Reaction	the energy level of (an emotional) response
Mood	the amount of pleasant, joyful, and friendly behavior, as contrasted with unpleasant, crying, and unfriendly behavior
Distractibility	the effectiveness of environmental stimuli in interfering with or in altering the direction of the ongoing behavior
Persistence	the continuation of an activity in the face of obstacles
Threshold of Responsiveness	the intensity level of stimulation that is necessary to evoke a discernible response, irrespective of the specific form that the response may take, or the sensory modality affected