Spending more time at school may increase intelligence, according to a study of Norwegian men. The research, in Proceedings of the National Academy of Sciences, suggested that an extra year in the classroom could boost IQ by nearly four points. The authors said that extra schooling had a “sizeable effect” on IQ in early adulthood. But they do not know if this applies to all children, or just those in this study. A link between a higher IQ and more education has already been established, the authors say. However, determining whether spending more time in school actually improves IQ is more difficult, as it is possible that children with a naturally higher IQ are those who choose to spend more time in the education system.                                                   –BBC