An interesting article in this week’s Economist reports on experiments showing that people in a competition, for example in an exam hall, do better when surrounded by fewer competitors. In the 2005 SAT exams in the USA:
The two researchers used data on the number of test-takers in each state of the union and the number of test-taking venues in that state to calculate the average number of test-takers per venue in the state in question. They found that test scores fell as the number of people in the examination hall increased. And they discovered that this pattern was also true for the Cognitive Reflection Test, another analytical exam.
Further experiments suggested that even when factors such as the differing amounts of distraction have been removed, if you know or feel you are competing against a smaller group, you will achieve more.
The article is here – it may require an Economist subscription, though.