Mental Arithmetic as a Function of Computerized Digit Rates, Gender, and Size of Audience

Abstract

Mental-arithmetic tests were given to 117 undergraduate volunteers (40 men and 77 women) using three rates (between groups) of digit presentation (1 sec., 2 sec., and 3 sec.) under three (within-group) sizes of audience (2 observers, 1 observer, and alone condition). Subjects were instructed to sum mentally three sets of 25 numerals ranging from 1 to 5 in computer-generated random sequences, under each of the three audience conditions. A mixed 2×3×3 split-plot analysis of variance of correct scores showed a significant main effect for rate of digit presentation, and post hoc Scheffé tests of multiple comparisons showed significant differences between the 1-sec. rate and each of the other rates (2 sec. or 3 sec.), yet no significance between 2-sec. and 3-sec. rates indicating a “critical threshold” has been identified with implications for computer-scrolled numerical information. Also, there was a significant two-way interaction between gender and size of audience. Post hoc Newman-Keuls comparisons showed women scored higher than men in the one-observer condition while men scored higher than women in the two-observer condition. Interpretations regarding interpersonal relationships and social inhibition were offered.