Robert Yerkes and John Dodson worked as psychobiologists in the beginning of the previous century.

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Candler Professor at Emory University and director of the Living Links Center at the Yerkes National Primate Research Center, both in Atlanta.

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The Yerkes Dodson curve (shown above), developed by two psychologists in the early 20th century, demonstrates the relationship between stress, or chronic arousal, and performance.

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Chicago-born financier Charles Tyson Yerkes, who bought various railways in London between 1900 and 1902, built Golders Green station in 1907, boasting that if he built people would come.

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This tradition goes back at least as far as the Yerkes Observatory in Wisconsin (the best in the world, a century ago), which was paid for by the builder of the Chicago elevated railway.

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The notion that moderate anxiety can be beneficial goes back at least to 1908, when Harvard psychologists Robert Yerkes and John Dodson posited that arousal (as they called it) enhances performance but only to a point.

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Then Yerkes and Dodson compared the results.

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Chen was building on research from Emory University's Yerkes National Primate Research Center, which has been working with capuchins for years because of their strong instincts for cooperation and working in groups (in the wild, they eat large squirrels, which require at least two monkeys to capture).

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