The educational psychologist Robert L. Thorndike showed that the quality of the Pygmalion study of the impact of inducing teacher expectations on IQ was poor. The problem with the study was that the instrument used to assess the children's IQ scores was seriously flawed.[5] The average reasoning IQ score for the children in one regular class was in the retarded range, a highly unlikely outcome in a regular class in a garden variety school. In the end, Thorndike concluded that the Pygmalion findings were worthless. It is more likely that the rise in IQ scores from the retarded range was the result of regression-to-the-mean not teacher expectations. Moreover, a meta-analysis conducted by Raudenbush[6] showed that when teachers had gotten to know their students for two weeks, the prior to expectancy induction was reduced to virtually zero.