Streaming
Evidence to suggest that streaming practices within schools contributed to differential educational achievement is not hard to find (quite the contrary in fact).
David Hargreaves ("Social Relations in a Secondary School", 1967), for example, noted that boys were streamed on the basis of "academic ability" from their first year onwards. After their first year, the streams (five in all - A to E) took-on a rigid character, such that it was almost impossible for a boy allocated to the bottom (E) stream to move into the top (A) stream. As Hargreaves notes:
"During the four years which a boy spends at Lumley school, it is quite possible for him to change streams several times. One of the boys in the present 4A began his career in the school in 1E, but such cases of movement from one extreme to the other are exceptional. It is more common for a boy to move one or two streams up or down; it is not unusual for a boy to move up or down one stream and then return to his original stream.".
Not only did Hargreaves find that there was a close correlation between social class and streaming (middle class children in the top streams, working class children in the bottom), but he also found that the experience of streaming helped to confirm each child into a self-perception as either a "success" or a "failure" (which suggests evidence for the concept of a self-fulfilling prophecy).
Additionally, because there was little movement between streams, pupil sub-cultures developed, which led not only to conflicts between teachers and pupils but also to "inter-stream", pupil-to-pupil, conflicts. In this respect, Hargreaves notes:
"The organisation of the school imposes severe restrictions on opportunities for interaction between boys from different streams, and is thus a major factor influencing the formation of friendships... Clint [a boy from the 4D stream], as "cock" of the school, and Adrian [a boy from the 4A stream], as school captain, are well-known and highly visible as leaders of their groups. They become representatives of their groups, embodiments of the values they support, and thus targets to their opponents.".
Similarly, Colin Lacey's study of "Hightown Grammar" (1970) noted the way streaming affected the behaviour of differently-streamed children and, in turn, affected their educational achievement. Lower stream pupils - mainly from working class backgrounds - increasingly came to adopt anti-academic attitudes and behaviour. Perhaps one of the most surprising aspect of this study is that this should have involved children who, at aged 11, were being classified educationally as amongst the most academically-able in the country as a whole. It is evident therefore, that the effects of streaming are pronounced, in terms of the child's self-perception as either "bright" or "dim", even when "objectively" the child is certainly not the latter.
The above sample of evidence does point to a "streaming effect", whereby differences in educational achievement are related to the different ways that children are categorised within the school. However, even though the evidence, when considered overall and in a much wider context, might be considered compelling, one problem remains with it as an explanation of differential educational achievement, namely, very few, if any, schools in Britain now adopt this type of streaming process - yet, as we know, differential educational achievement is still in evidence...
In this respect, while we should not reject streaming as evidence in this case it is important to keep in mind that while it may have contributed to one form of differential educational achievement, the fact that it now a largely-discarded practice within schools (at least in Britain) suggests that it is not a valid explanation for current forms of differential achievement.