The author has tried to verify the validity of the judgement, so frequently pronounced, about the pupils’ unsatisfactory results being mainly due to their intellectual inability. For this purpose he chose from among 1,156 pupils with unsatisfactory results in the region of Southern Bohemia those whose failure, in their teachers’ opinion, was due to lack of talent, and analysed the actual influence of this factor compared with other negative factors influencing the pupils’ classroom attainment. He found that all the pupils were affected by a number of negative social factors which may be supposed to have a strong influence on the pupil’s school results. He therefore considers the teachers’ Judgement about a pupil’s talent unreliable, concealing other, external causes of unsatisfactory results at school. In order to verify what role intellectual abilities played in the unsatisfactory results of the pupils at the Basic Nine-Year School, the author made another selection from among the above-mentioned group of pupils by the statistical method. With a group of 58 pupils thus selected he carried out part of Wechsler’s Test. He intentionally chose the sub-tests, in which the dependence of the pupil’s performance on knowledge gained at school is reduced to the minimum. He came to the conclusion that 70 per cent of the pupils taking part in the test were intelligent enough to meet the requirements of the Basic Nine-Year School curriculum and the causes of their unsatisfactory results were to be sought elsewhere than in the intellectual sphere, i. e. in the social conditions in which the pupils lived. On the basis of his findings the author warns against one-sided use of the pupil’s classroom attainment as a criterion in judging the intellectual abilities of the children, in streaming them at school and in choosing their careers. He is of the opinion that there are intellectual reserves among children coming from the less favourable social conditions, especially from the rural areas.