History of the 11+
The 11 Plus exam was introduced during the time of the Tripartite System(Wikipedia link) in 1944, having been created by the Butler Education Act 1944(Wikipedia link). It was used to determine which educational route a pupil would follow after their primary education, at the time these routes being a grammar school, a secondary modern school or a technical school. The 11+ created a fierce competition for grammar schools, which gave pupils the best education academically, and as such, pupils were seen to ‘pass’ or ‘fail’ the 11+. When a pupil ‘failed’ their 11+, this would often remain with them for a long time.
The original 11 Plus exams put emphasis on skills rather than financial resources, as different schools could provide teaching for different skills.
Nowadays, the 11+ is used to test pupils academically in a range of subjects, to decide whether they are able enough to attend a grammar school. Different areas test a variety of these subjects, not everywhere is the same, some areas test only 3 of the 4 possible subjects. The current tests, written predominantly by CEM and GL Assessment, are taken in addition to SATs, which cover the National Curriculum for Key Stage 2.