MENTAL PROCESSES INVOLVED IN RAPID LOGICAL REASONING

S medslund , J. Mental processes involved in rapid logical reasoning. Scand. J. Psychol ., 1968, 9, 187–205.—Approximate reaction times of adult subjects were recorded in three studies of addition and subtraction of units, and in one of transitive inference. Transformations such as from 'V has more than H' to 'H has less than V' were found to be important determinants of RT in additionlsubtraction. Under some conditions subjects preferred to combine the first two elements in a triad of operations first, under other conditions they seemed to select inversions (V + 1 & V−1) first. Symmetries (V + 1 & H +1) were apparently never preferred. All transitive tasks seemed to be converted into normal form (A>B ∓ B>CorA < B & B < C) before they were solved.