Science of Sex: Habituation of Sexual Arousal (The Coolidge Effect)

February 24th, 2018

Welcome to the Science of Sex, a feature I've managed to publish on Of Sex and Love for a whole year (albeit not necessarily when I promise to). In this monthly segment, I discuss the science of sexuality in an easy-to-digest format that’s accessible to the casual reader. I will also follow up with some extended reading material for people who want to know more about the subject of each post.

Today's post explains why it's harder to feel aroused by your partner after you've been together for a long period.

Check back every second Saturday of the month (ish) for new Science of Sex posts.


The so-called Coolidge Effect is a biological occurrence wherein a member of a certain species will experience renewed sexual vigor when a new potential mate enters the picture. In short, even an exhausted male will suddenly be ready to mate if a new female enters.

The Coolidge Effect is apparently named after president Coolidge, who'd had a discussion with his wife about a Rooster's prowess upon visiting a farm. When FLOTUS inquired into the rooster's sexual ability, POTUS apparently remarked upon the number of hens available.

Research indicates that several species experience the Coolidge Effect.  It can also occur in females, but the effect is heightened with males of a species. It may take longer for habituation to effect a woman's sexual respond than a man's. The research is currently conflicting.

Humans are definitely not immune to this, and it doesn't just apply to sexual activity. The Coolidge Effect explains why arousal increases when new stimuli (women) enter the picture. One study examined men's' arousal when exposes to the same stimulus as compared to arousal levels when the men experience more various stimuli.

Similarly, men who repeatedly view porn of the same actress will experience faster ejaculation, and the sperm contained in the ejaculate may actually be healthier!

The term for getting used to the same sexual stimulus is known as habituation, and it's exactly why people grow to need novelty in long-term sexual relationships. It strikes me that the Coolidge Effect can even explain why someone who has new sexual partners, consensually or otherwise, might experience renewed desire for their original partner.

Habituation of sexual arousal is worth looking into deeper. Researchers have found that while genital response will decrease to repeating the same stimulus, people can still subjectively feel aroused. Scientists were especially surprised to learn that this happens in men because men often feel mentally and genitally aroused simultaneously than women (concordance).

The proposed explanation for the Coolidge Effect is the same for many sexual theories. A male of the species will be able to produce more offspring if his desire can be triggered by multiple partners and quickly after new potential partners become available.

What does all this mean? If you've had sex with the same person for quite some time, especially if it's the same sort of sex, arousal might dip. Enter a new, attractive person, and you'll find yourself desiring sex again. Keeping things novel is one way to ward off the Coolidge Effect and minimize habituation, but it doesn't mean that something's inherently wrong with your relationship.  

Habituation may not be permanent, either. In at least one study, men found that desire again increased after a period of time.

Further Reading