It reckons that the more tests you do the less effort you put in and the more upset you get about doing them.
Most people think doing tests helps to make you cleverer, but the report doesn't agree, saying the more you do the worse your results get.
The problem is worst for girls and pupils who aren't very good at school.
To try and make things better the Assessment Reform Group, who carried out the survey, have come up with some ideas including less comparison of scores.
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It's best to be calm about exams
