The Coolidge effect is the tendency of males of every tested mammalian species to perform at their sexual peak when introduced to a new receptive female. The term comes from this old joke:
President Calvin Coolidge and his wife visited a poultry farm one day, and, during the tour, asked the farmer how he managed to produce so many fertile eggs with such a small number of roosters
The farmer explained that his roosters performed their duty dozens of times each day.
"Perhaps you could point that out to Mr. Coolidge," replied the First Lady in a pointedly loud voice.
The President, overhearing the remark, asked the farmer, "Does each rooster service the same hen each time?"
"No," replied the farmer, "there are many hens for each rooster."
"Perhaps you could point that out to Mrs. Coolidge," replied the President.
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