Coolidge Effect

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What is Coolidge Effect?

Coolidge Effect is the resumption of some copulation by a male that has already stopped with one receptive female, once a different receptive female is made available.

The Coolidge effect describes the reinitiation of sexual behavior in a sexually satiated animal in response to a novel receptive mate.

That sentence opens Fiorino, Coury, and Phillips in 1997. Sexual satiety here is a stop inside one laboratory session, after repeated mating with the female on hand. It is not a diary of desire across years with the same person. Mere Exposure Effect is a rise in liking after repeated contact with a stimulus. The two pages point in different directions and should not be stacked into one story about familiarity. Donald A. Dewsbury’s 1981 review, read here as the abstract, defines the same restart: mating returns in males that have reached sexual satiation with one female when that female is replaced by a novel female. The abstract also says results differ by species, by the test’s design, and by the conditions. A popular line treats the restart as a staircase of lost interest in one spouse, reversed at once by any new person, and calls that staircase the biological price of loyalty. The rat tables do not measure a spouse.

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Coolidge Effect in 3 Depths

• Beginner: After a male rat has mated until he meets the session’s stop, a new receptive female can bring some mating back. The return is often small. It is the same afternoon’s second partner, not a new chapter of a life.
• Practitioner: When a book or a feed uses the name for a couple, write four cells before you accept the label. Who stopped, by what clock, who was introduced, and which act returned. If those cells are empty, the page in front of you is a metaphor.
• Advanced: A motor pattern that looks like ejaculation can return while sperm do not. A dopamine rise can be real and still leave the second hour far below the first. Treating either rise as proof that a new person restores “vitality,” or that genes are thereby spread, skips the counts.

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Origin

Coolidge Effect, as a printed scientific name, is in Wilson, Kuehn, and Beach, Journal of Comparative and Physiological Psychology 56(3), 1963, pages 636–644. Quote Investigator checked the hard copy. The journal received the article on 18 August 1962. On page 641 the authors say the phenomenon has been termed the Coolidge effect and cite R. E. Whalen, 1959, a paper read at the Western Psychological Association. The 1963 article does not tell the farm joke. Its abstract is the behavior: 25 male rats mated with 25 estrous females until an arbitrary exhaustion criterion. Replacing the original female with a new estrous partner sometimes brought mating back, including one or more further ejaculations. Taking the original female out and putting her back had only a slight stimulating effect. A female that had just mated with another male was more likely to restart activity. An unmated estrous female was the most effective swap. The joke enters the record later, in Beach’s own letter. Quote Investigator, 30 March 2018, reports a letter from Frank A. Beach, then professor of psychology at the University of California, Berkeley, printed in the 1974 fourth edition of Principles of General Psychology. Beach said he introduced the term, and that it referred to an old joke. In the letter’s telling, the President and Mrs. Coolidge were shown around an experimental government farm. At the chicken yard she noticed a rooster mating very often, asked how often, and was told dozens of times each day. She said to tell that to the President. He asked whether it was the same hen every time, heard that it was a different hen, and said to tell that to Mrs. Coolidge. Beach presents this as a joke. The letter is not minutes of a farm visit, and this page does not treat it as one. Beach’s letter, as Quote Investigator reads it, also dates the laboratory work. He and Lisbeth Jordan studied the sexual behavior of rats in 1955. A male could copulate only a limited number of times before exhaustion. Alan Fisher found that a new female increased the number of encounters. Beach’s group replicated Fisher, and Dick Whalen reported that work at the 1958 meetings of the Western Psychological Association. The 1963 bibliography, as Quote Investigator read it, lists Whalen under 1959, not 1958. Both years stay. The published exhaustion paper those sentences point toward is Frank A. Beach and Lisbeth Jordan, Quarterly Journal of Experimental Psychology 8, 1956, pages 121–133. That paper was not re-read. No recovery interval from it is on this page. Fisher’s larger totals did not become the standard size of the effect. Sigmund Hsiao, Psychonomic Science 14, page 1, January 1969, DOI 10.3758/BF03336392, reports Fisher’s 1962 means as 12.4 ejaculations and 85.5 intromissions when the female was changed, against 6.9 ejaculations and 43.0 intromissions when she was not. Hsiao’s own test used 48 Sprague-Dawley males in three equal groups and watched until 45 minutes passed with no sexual response from the male. Changing the female at once, or after 15 minutes of the refractory period, did not change the course of satiation. Hsiao writes that other reports of the effect were only about one or two extra ejaculations, and that no other result approached Fisher’s. Fisher’s 1962 paper was not re-read. His means appear here only as Hsiao states them. Dewsbury, Psychological Bulletin 89(3), May 1981, pages 464–482, was not re-read past the abstract. The abstract says the finding had already been carried over to human behavior, including predictions about monogamy, and that different paradigms must not be folded together. A change of female before satiety, a roomful of females, a change between test days, a new room, and a choice test are different designs.

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Key Points

Four readings keep the name, the size of the restart, the chemistry, and the human audiotape apart. A feeling of restlessness in a long relationship is not yet any of them.

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Applications

Use the name only after the four cells are filled: the stop, the clock, the new partner, and the act that returned. Then decide whether the note in front of you is a rat session, a tape, or a story about loyalty.

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Case Study

In 1997 Dennis F. Fiorino, Ariane Coury, and Anthony G. Phillips, in the psychology department at the University of British Columbia, published a microdialysis study in The Journal of Neuroscience 17(12), 15 June 1997, pages 4849–4855, DOI 10.1523/JNEUROSCI.17-12-04849.1997. They sampled dopamine in the nucleus accumbens, a forebrain region tied to motivated behavior, while male rats mated, stopped, and met a second female. The journal file was not opened as a PDF. The counts below are the paper’s Table 1 and the results sentences carried on the journal page. Training used a sliding screen that split the chamber. The male went into the large side. Fifteen minutes later a female was placed behind the screen for 15 minutes. The screen then came away and the pair had 30 minutes to copulate. Three training sessions ran, one every four days. Every rat met the performance criterion in every session. The paper’s wording of that criterion is not copied here. On the test day, samples were 15 minutes long. With the first female, dopamine rose 44 percent above baseline while she was behind the screen, and reached 95 percent above baseline in the first copulatory bout. It returned to baseline in the 30 minutes during which no mounting occurred. Putting her behind the screen again, and then allowing contact without mounting, did not lift the group mean above the new baseline. Three of the five males did resume copulation when she was returned. In those three, dopamine rose 25 to 47 percent while she was behind the screen and 13 to 37 percent during copulation, relative to the sample just before her return. The group mean and those three males are both in the paper. They are not the same summary. Table 1 is five males except where it says otherwise. With the first female, the first hour averaged 16.0 mounts, 37.0 intromissions, and 4.2 ejaculations. Total ejaculations before the satiety criterion averaged 7.8, range 6 to 11. Time to sexual satiety averaged 144 minutes, range 105 to 195. She was presented 2.0 times on average, range 1 to 4. After 15 minutes with no copulation, the second female went behind the screen. That presentation was a 12 percent dopamine rise from the latest baseline and was not statistically significant. Renewed copulation in the next sample was a 34 percent rise. Over the three samples after that, dopamine was back at baseline while weak copulation continued. In the first hour with her, mounts averaged 11.4, intromissions 11.2, and ejaculations 0.6. The intromission drop and the ejaculation drop are marked at p less than 0.05 and p less than 0.01. Ejaculation latency and the postejaculatory interval for the second female are printed for two males, 512 seconds and 850 seconds. This page does not turn 0.6 into a head count. The lesson is that a second receptive female can be followed by more dopamine and by some copulation after the first female has brought the male to the paper’s satiety line. The same table shows the first hour with her producing far fewer ejaculations. The boundary is the sample. Five rats, one laboratory, probes in the nucleus accumbens, and a second female on the same day. The 34 percent is one 15-minute sample, not a trait and not a couple.

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Boundaries and Failure Modes

The restart fails as a general law wherever the test changes species, sex, clock, or what “ejaculation” means. Three boundaries matter before anyone exports the hour. Hsiao’s 48 males are the procedural boundary. Under a 45-minute stop with no sexual response, and with the female changed either immediately or after 15 minutes of the refractory period, satiation ran the same course. A procedure that looks similar can print no effect. Fisher’s much larger totals remain his report, as Hsiao quotes them, not the size to expect. José L. Tlachi-López, Jose R. Eguibar, Alonso Fernández-Guasti, and Rosa Angélica Lucio, Physiology & Behavior 106(5), 2012, pages 626–630, DOI 10.1016/j.physbeh.2012.04.020, were not re-read as a PDF. The publisher text says the males reached satiety after 10.6 ejaculations on average, range 6 to 18, and that 16 of 18 resumed copulation with an unknown female. The abstract says most of them showed the motor pattern of ejaculation, and that no sperm were found in the uterine horns and no seminal plug was found in the vagina. Sperm count in the epididymal caudae fell 44 percent after that behavioral ejaculation. A body that goes through the motions is not, in that abstract, a deposit of sperm. The unfinished contrast of intromission counts in the publisher excerpt is not printed here. Elisa Ventura-Aquino and Alonso Fernández-Guasti, Physiology & Behavior 120, 15 August 2013, pages 70–76, were read as the abstract. Female rats in proestrus mated for three hours with two males, 90 minutes each. Both males were sexually active and unknown to the female. Hopping and darting rose again when the male was changed only in the condition where the female could pace the contacts. Lordosis stayed at its maximum the whole time. No frequency from that paper is on this page. A female rat that can leave and return is not a male rat at ejaculatory satiety, and two strangers in one afternoon are not a human pair. The common misuse is to take the partial rat restart as a law of human loyalty. O’Donohue and Plaud’s five men habituated to one audiotape and stayed responsive when the tape changed. Their mean spontaneous recovery, with subject 1 left out, was 78.76 percent of the maximum penile response in the first constant-stimulus session. Subject 1 was left out of that mean in the paper. Five students and a tape do not become a spouse, a clinic, or a prediction about who will keep a promise. Dewsbury’s abstract already said the animal result had been carried over to human monogamy, and that paradigms must stay apart.

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Common Misconceptions

The name is easy to stretch. Each stretch below replaces a counted session with a bigger claim the session did not test.

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Related Concepts

These neighbors are easy to fold into the same popular paragraph. Each one measures something else.

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One-Line Takeaway