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Biomedical subjects

G Jahoda

Publications and source records attributed to G Jahoda.

At least 19 recordsLinked to original sources
PubMed2000

Piaget and Levy-Bruhl.

Levy-Bruhl exerted a powerful influence, seldom considered, on Piaget. The Levy-Bruhlian thesis of a "pre-logical mentality" characterized by "mystical participation" is outlined, together with its initial reception. The first evidence of Piaget's interest in it dates from 1920, and when he began his studies of children's thinking he compared it with that of 'primitives," also adopting Levy-Bruhl's concept of "participation." By 1928 Piaget had elaborated a theory of the social foundations of different types of thought, which he regarded as also explaining the alleged similarity between the thinking of primitives and children. Both are subject to constraint, primitives by elders and children by parents and teachers. Logical as opposed to pre-logical thought was said to depend on cooperation in free social interaction. Piaget continued to maintain essentially the same views long after Levy-Bruhl himself had renounced the notion of pre-logicality.

History, 19th Century↗
PubMed1988

Patterns of visual-spatial performance and 'spatial ability': dissociation of ethnic and sex differences.

Is there a common basis for the ethnic and sex differences that are characteristically obtained on psychometric tests of spatial ability? Three experiments approached this question by observing subject differences in the recognition and reconstruction of visual-spatial displays. The pattern of performance on these experimental tasks was compared with that on a traditional spatial ability test. In the first experiment, two samples of 40 students, balanced for sex, from Zimbabwe and Scotland respectively, attempted a forced-choice recognition task for meaningful scenes. Both ethnic groups and both sexes showed equivalent performance. The same subjects then undertook a task involving the reproduction of an arrangement of blocks into two-dimensional plan and elevation views. On this task, involving spatial reorientation, the Zimbabweans made over three times as many errors as the Scots. In a third experiment the requirement for spatial reorientation was added to the original recognition task and this was performed by a further 40 subjects. A significant difference between ethnic groups now emerged and this effect covaried with spatial ability. Again, however, no sex difference was observed. The overall pattern of results points to spatial reorientation as a major factor in the cross-ethnic differences. The absence of a sex difference on the experimental tasks contrasts with its appearance in both samples on the spatial ability test and represents a puzzling obstacle to our current understanding. This dissociation of sex and ethnic differences provides evidence against the hypothesis that they stem from the same source.

Adult↗
PubMed1980

Sex and ethnic differences on a spatial-perceptual task: some hypotheses tested.

The most prevalent version of the environmental hypothesis, by Sherman (1967), would predict a sex difference in spatial performance in Scotland but not in Ghana. With regard to the particular task used, namely 3D mental rotation, the same prediction would arise on the basis of Serpell's (1979) 'specific experience' hypothesis. Subjects were 40 boys and 40 girls in both Ghana and Scotland, equated for years of education. The results showed a sex difference of the same magnitude in both cultures, thereby throwing doubt on purely environmental interpretations. The findings also clearly argue against a genetic hypothesis put forward by Jensen (1975).

Adolescent↗
PubMed1979

On the nature of difficulties in spatial-perceptual tasks: ethnic and sex differences.

The common claim that Africans exhibit a general weakness in handling spatial relationships is questioned, as is that of a general male superiority. The aim of the study was to identify some of the specific areas in which ethnic and sex differences may be located. A sample of 72 Ghanaian children evenly divided according to sex and early, middle and later stages of primary schooling were administered a series of tasks adapted from Piaget & Inhelder (1971); the same tasks were given to an equivalent group of Scottish children. On a block construction task involving memory the Ghanaians performed at the same level as the Scots when working from models, but not when the presentation consisted of photographs or line drawings (P less than 0.001). On two tasks requiring mental rotation of shapes and, subsequently, the actual assembly of shapes into regular figures, the Ghanaians again experienced more difficulty (P less than 0.001). Intercorrelation of scores on the various tasks suggested that the underlying structures of abilities may differ in Ghana and Scotland. The pattern of sex differences was exactly the same in both cultures. Girls did less well with the block construction (P less than 0.001), but there was no significant sex difference on mental rotation or shape assembly.

Adolescent↗
PubMed1978

Cross-cultural study of factors influencing orientation errors in the reproduction of Kohs-type figures.

The aim of the study was to examine pattern difficulty as a general factor influencing orientation errors, and to explore psychological differentiation and task perception as variables accounting for cross-cultural differences. Samples of 30 boys and 30 girls in Ghana and Scotland were tested with a specially devised apparatus under two treatment conditions. Results confirmed the effect of pattern difficulty, but the extent of psychological differentiation was only indirectly related to orientation errors. Variations in the manner subjects perceived the nature of the task appeared as a major determinant of cross-cultural differences.

Adolescent↗
PubMed1976

Reproduction of Kohs-type figures by Ghanaian children: orientation errors revisited.

First, a relationship was postulated between the experienced difficulty of patterns and the amount of disorientation of their reproductions. Secondly, while the major determinants of gross orientation errors among Africans seem to have been established, this in itself fails to explain why Europeans are little affected by them. It was proposed that the underlying factor might be the development of the concept of horizontality, which reduces dependence on the perceptual pull of the prevailing spatial framework. These notions were tested with 44 Ghanaian schoolboys aged between 10 and 16. The first relationship was clearly confirmed. As for the second, there was some association between horizontality and rotation errors, but it failed to account for a major part of the variance. Ex post facto exploration of the data strongly suggests that degree of psychological differentiation is likely to be the key factor influencing rotation error.

Adolescent↗