Measurement of Reaction Tendencies

While the majority of reports dealing with the relation of temperament to reactivity level have been of a qualitative kind, methods for the precise measurement of involuntary reaction tendencies are being rapidly developed.

the following nine groups of nervous symptoms which can be rated quantitatively in terms of the number of trait-actions per stated unit of time.

1. Oral (sucking thumb and finger, biting nails, protruding tongue)

2. Nasal (picking, scratching or wrinkling nose)

3. Hirsutal (pulling and twisting hair, scratching head)

4. Irritational (scratching body)

5. Manual (picking fingers, waving hands, clenching fists)

6. Ocular (rubbing eyes, blinking eyelids, excessive winking)

7. Aural (pulling and picking ear)

8. Genital (manipulating genitalia, rubbing thighs)

9. Facial (excessive grimacing, twitching muscles)

There was no relation between the amount of nervousness and age, and members of a family tended to resemble each other more with respect to nervous symptoms than persons selected at random. The oral traitaction scores showed the highest reliability and were the most predictive of general nervousness and excess reactivity.

The Role of Muscular Tension

The possible rôle of muscular tension in differentiating individuals is worth special attention, both because of the theoretical importance of tension in neuromuscular action and because of direct evidence. Certainly individuals might differ both in their normal level of waking tonus and in their ability to summon tonus increments; and since the excitation derived from such processes probably determines in large measure reaction to other forms of stimulation, tension might be positively correlated with degree of reactivity, irritability, and certain other aspects of temperament. We do not need to confine our analysis to theoretical supposition, however, for a body of experimental evidence on the problem is rapidly accumulating.

Hypertension is frequently noted in neurasthenia, while many of the more serious psychotic cases exhibit great muscular rigidity and restlessness. It is apparent that individual differences in tension are not a fortuitous matter but a highly significant one. Assuming that the proprioceptive impulses coming into the central nervous system act to lower thresholds for all stimuli, individuals who possess a neuromuscular mechanism habitually geared to high pitch would tend to exhibit irritability and excess reactivity.