In an attempt to beat exam stress, some schools in the UK are offering pupils chocolate and access to relaxation rooms, academics told an education conference.
Researchers at Edge Hill and Manchester universities have urged that parents and teachers are putting the wrong kind of pressure on teenagers to succeed.
The study has been presented at the British Educational Research Association (BERA) conference in Manchester.
The study found that higher anxiety usually leads to lower scores.
Lead researcher Dr Dave Putwain said: "I know of one school that gives anxious children chocolate and a pat on the head immediately before an exam.
"Pupils at another school I have visited can spend some time in a relaxation room that has soft lighting, comfortable furniture and soothing sounds."