Rosenthal and Jacobson (1968): Study of Oak community school, a California primary school
- They told the school that they had a test that would identify pupils who would spurt ahead - this was untrue
- Researchers tested all pupils and picked 20% of them randomly and told the school that these children were the 'spurters'
- 47% of the identified spurters had made significant progress; teachers' beliefs about the pupils had been influenced by the test results, they then conveyed these beliefs to the pupils through the way they interacted with them
- If teachers believe a pupil to be of a certain type, they can actually make him or her that type
- What people believe to be true will have real effects - even if the belief was not true originally