Temperament and Narrowness of Attention

Abstract

Callaway and Stone (3) suggest that the pharmacologically aroused individual shows narrowed attention. In Easterbrook's (4) terms such a person restricts his range of cue utilization and hence does well on tasks such as the Stroop test which require exclusion of irrelevant cues. Agnew and Agnew (1) showed that Stroop test performance is slightly (but not significantly) facilitated when electric shock is used to induce high drive. Now Broadbent (2) puts forward the hypothesis that introverts are chronically aroused. If so, they may have narrowed artention and their Stroop test performance may be relatively better than that of extraverts. From a group of 30 British undergraduates two samples were chosen, the 12 most sociable (Heron Inventory scores 0 to 3) and the 12 least sociable (Heron Inventory scores 6 to 10). These students were given the Stroop test in a version similar to that of Agnew and Agnew. Time to complete Card I1 (color naming) and Card 111 (colors on incongruous color names) was taken and the measure used in analysis was the ratio III/II X 100. The higher this ratio the greater the interference effect. The mean score for introverts was 184.2 and for extraverts, 150.8. Contrary to hypothesis, Heron introverts showed higher color-word interference (U = 27, p < .02, two-tailed test). A model of Srroop test performance which would predict this result has been suggested by Leedy (cf. 5). Word naming (H,.) is a more dominant habit than color naming (H,). In response competition, interference is a function of (H.. - H,), and response strength is given by D(Hw - H,). If introverts have higher intrinsic drive, they will do worse than extraverts in conditions of interference. The two theoretical approaches are not incompatible but neither is complete. Callaway and Stone suggest that high induced arousal enhances expectancy for less probable stimuli (this would tend to increase H.). Leedy, however, regards arousal as affecting D alone. The influence of high arousal on Stroop performance is not clear-cut. We need to know whether the task itself is highly arousing, we may need to distinguish intrinsic from induced drive and to ascertain whether drive affects H, and H, independently (5). Callaway and Stone's model of narrowed attention requires some amplification to embrace both their own and the present result. REFERENCES