The Coolidge effect illustrates how novelty can be a powerful aphrodisiac.
(http://www.trickfilmwelt.de/foghorn.jpg)
During his administration President Calvin Coolidge and his wife visited a Purdue University experimental farm and toured it separately.
A grand rooster marched to the fence to eye the strangers in the first tour group. Seeing the majesty of this well-feathered dude, Mrs. Coolidge asked, "what creature is this?"
"That is Ulysses, our Rooster, Mrs President" stated their guide (a young man of note).
Then as he moved away, and in a flurry of feathers and rooster-dudeliness abruptly and quite violently copulated with a hen (note - as a PURDUE farm it was a hen, unlike the rooster-to-rooster copulation often observed at IU farms)
Mrs. Coolidge asked how often this happened, and was he the ONLY rooster?
The guide replied that since they have only 60 hens, yes, Ulysses was the only dude in the henhouse. And mating - indeed it happened several times per day. This prompted the First Lady to say,
"Young man, I require you promise to mention that fact to Mr. Coolidge."
The guide, a dutiful dude, complied reluctantly; "Mr. President, I must tell you that your wife required that I mention that Ulysses, our only rooster, mates several times each day, Sir."
Thus informed, after a moments pause, the President replied with genuine dudely aplomb. He asked; "Tell me young friend, is it always with the same hen?"
When told that it was a different one each time, Silent Cal then said, "I insist that you mention that to Mrs. Coolidge at lunch."
So shall it be written, and so was it done. The stamp of the Dude applied directly upon her feminine wiles. (and it had the characteristics of a well-worn work boot's sole upon her female connivance and unrestrained douching-of-dudes)
All homage to Coolidge - the penultimate Dude.
The young Dude when on to earn his PhD by studying the infinite detail of this encounter, and the phenomenon of repeated arousal when around unique and receptive vaginal opportunities is to this day dubbed; "The Coolidge Effect"
Thus, the Coolidge effect refers to the stimulative power of sexual novelty. It is operative in most species, including humans.
"Be sure you inform your Mrs., preferably at lunch." (my channeling of President Dude's spirit)
"hens"
(http://www.vaginalady.com/images/2003/Halloween2003_4.jpg)