The effect of thematic content on the ‘Wason selection task’

This paper concerns the differential effects of use of ‘thematic’, rather than abstract (symbolic), content on the ‘Wason selection task’. An effect of thematic content has been reported several times, originally by Wason & Shapiro (1971), but Manktelow & Evans (1979) report five experiments that failed to obtain an effect and argue against the validity of the content effect in general. However, it is pointed out that four of their experiments use a novel content and that there are previous reports of non-effective content in the literature. It is concluded that a particular type of thematic content cannot be treated as a ‘random sample’ of thematic content in general, and that their argument thus rests upon their failure to produce an effect of the specific (’towns and transport’) content used by Wason and Shapiro. This produces an essentially empirical controversy which is settled in two ways. First, Manktelow and Evans’s criticisms of two previous replications are shown to be misleading. Second, an experiment is reported that exactly copies the Wason and Shapiro design and produces a significant effect of content. It is concluded that the Manktelow and Evans result most probably was due to a Type 2 error. Finally, a hypothesis is developed to account for both the effect of certain types of content and the lack of effect of others, including that used in Manktelow and Evans’s first four experiments.     

Two subjective scales of number

The way in which the apparent magnitude of numbers grows with their absolute magnitude was measured with a modified version of the direct technique Marks and Slawson (1966) used to determine the psychophysical exponent for loudness. This modified technique required subjects to estimate how evenly and randomly a sequence of integers appeared to sample the numerical continuum. The results indicate that the apparent magnitude of numbers increases with a decelerated power function of their arithmetic magnitude when a series samples from an open-ended range. However, when an upper boundary of the range is specified, the subjective scale seems to be linear. Random productions of numbers parallel the results found with judgments of presented sequences. The two scales of number provide the basis for an interpretation of the difference between magnitude and category scales: that subjects use numbers differently when the response scale is open-ended Imagnitude estimation than when it has a fixed upper limit tcategory scale. Given the assumption that subjects use numbers in this way in the two tasks, the qualitative relation between magnitude and category scales is predicted.     

Integrality over different paradigms: Card sorting and two-stimulus matching

Orthogonal interference—indicating the cohesiveness between geometrical dimensions—was examined using two separate tasks: (1) card sorting and (2) two-stimulus matching requiring same/different responses. The card-sorting results of the present experiment were contrasted with the results of our previous research (1977, 1979) which used the two-stimulus matching task. Results were generally similar in that the orthogonal interference and, consequently, the degree of integrality/separability were the same for both tasks. Evidence was found for the emergence of a new nominal dimension. This and other results are only compatible with a weaker form of the global-to-local hypothesis of perceptual processing.     

Antagonistic effects of adjacency and apparent speed in induced movement

Two experiments concerning induced movement are reported. The hypothesis was that when outline inducing frames were used, object-relative displacement was modified by two variables, adjacency and apparent speed. Adjacency is directly related to the magnitude of induced movement. Small outline frames are high in adjacency, and so small frames should be powerful generators of induced movement. On the other hand, several investigators have found the speed of the inducing frame to be inversely related to the magnitude of induced movement. It is hypothesized here that this effect of speed was determined by apparent speed (not real speed), and if so, since small objects appeared to move faster than large ones, a small outline frame should be a relatively weak generator of induced movement. In the first experiment, this hypothesis was tested using single inducing frames. In the second experiment, this hypothesis was tested using two inducing frames presented simultaneously. The implications of these experiments were discussed with regard to other theories of induced movement.     

Behavior of depressed subjects in problem solving groups

This study investigated leadership selection in groups in relation to level of depression of group members. On the basis of MMPI-D and DACL scores 66 subjects were organized into groups of six to eight people consisting of all depressed, all nondepressed, or half depressed and half nondepressed subjects. Subjects performed a problem solving task alone and in groups and completed a questionnaire on leadership choice and group performance. Results indicate that nondepressed group members talked more frequently, were rated as more important contributors, and were selected as leaders more frequently than depressed members. In addition, mixed groups were perceived as more efficient and enjoyable by group members than the unmixed groups. There were no significant differences between depressed and nondepressed subjects on performance of the problem solving task whether working alone or in groups. Results were discussed in relation to other literature on the interpersonal behavior of depressed persons.     

Children's use of semantic analysis in the interpretation of missing subjects: Further evidence against the MDP

Preschool and many older children often have difficulty understanding who carries out the complement action (e.g., to go in sentences such asMary promised John to go; this is so, even though they easily understand this information in sentences such asJohn told Mary to go. C. Chomsky (1969) proposed that children's errors arise from the overgeneral application of a purely structural Minimal Distance Principle. Maratsos (1974), however, hypothesized that children err by overgeneralizing a different principle which he called the Semantic Role Principle. According to this principle, the Goal-Recipient of the spoken message, not the closest noun phrase, is understood as the person who carries out the act referred to by the infinitival complement. The two studies reported here were designed to determine which of these principles children use. Preschool children were taught to understand a specially designed novel construction. The children then acted out sentences containing related but novel uses of the construction such that they would respond differentially according to which interpretive principle they used. The results strongly favored the Semantic Role Principle, rather than the MDP described by Chomsky (1969), or a related, more complex MDP described by Rosenbaum (1967). It is further discussed how children's formulation of the Semantic Role Principle, rather than the MDP, might arise from their prior analyses of related constructions, such as the imperative construction, rather than following from an innate preference, as suggested in Maratsos (1974).This research was supported by the NICHD under Grant #5 R01 HD09112-02 given to M. P. Maratsos.