The purpose of this monograph is to describe a number of studies that the author has carried out, which offer some evidence for the existence of a few environmental factors which appear to influence children's performance on both ability and attainment tests. The notion is developed of how children's motivation to learn, and hence their level of performance may be affected by some none too obvious factors in their school environment. In Chapter one, the argument is advanced that the very concept of intelligence--at least as it has been understood by many teachers--can of itself exert an influence both on the structure of an education system and on the expectations that teachers develop of their pupils' capabilities. In Chapter two, a study is reported which illustrates how pupil performance on non-verbal, supposedly more or less culture-free or culture-fair, tests can be influenced by factors which are quite independent of schooling and which appear to arise solely from differences in the cultural backgrounds of the children concerned. A study is reported in Chapter three suggests that the intimacy of daily contact between parent and child is of no little importance in determining the pupils' level of achievement in school. Other studies deal with the influence of the general atmosphere of the school, the influence of curriculum factors, factors influencing teacher expectations, and pupil expectations and aspirations. (Author/JM)