The term Coolidge effect describes a phenomenon—seen in nearly every mammalian species in which it has been tested. In short, mates tire of intercourse with their present partner and get excited at the prospect of a new sexual partner. And, it has been seen in both male and female species.
Why? Because it’s a biological mechanism. The amount of dopamine declines with a familiar mate, but shoots up with a new mate. This increases the odds of genetic diversity in offspring.
Pair-bonding species (like humans) have biological mechanisms that allow them to find sustained relationships rewarding. But these are in tension with the more ancient Coolidge effect.
How we choose to manage our sexual desire can affect our perception of how rewarding a familiar partner is (as compared with a novel one). We can mute the Coolidge effect by engaging in daily bonding behaviours and side-stepping post-orgasmic neurochemical shifts with Synergy.
Dr. Heike Melzer discusses the Coolidge effect in this TEDx talk. Click “CC” to turn on subtitles.
Also see Post-climax effects – Dopamine.