Bold Fish, Timid Fish, Smart Fish, Dumb Fish: Introversion, Extroversion and Risk-taking


When Lee Dugatkin, Professor of Biology at the University of Louisville, placed guppies in a tank from which they could view predators in another tank, some of the fish swam up to the barricade to observe the predators; he named these “Bold” fish. Others – the “Timid” fish – swam the other direction.

When all the fish were placed directly in the tank with the predators, the Bold fish swam right up to the predators– and were eaten. Their survival rate at 36 hours was roughly half that of the Timid fish, and at 60 hours their survival rate was zero compared to 40% for the timid fish.
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