Compersion

The word does not have a Greek or Latin pedigree. It was coined in 1980 at the Kerista Commune, a polyfidelitous group in San Francisco's Haight-Ashbury that practiced rotational sleeping schedules within tight-knit family units. According to a contemporaneous account preserved at Polyamory in the Media, fifteen Keristans gathered around an alphabet board on November 28, 1980 and asked for the antonym of jealousy; the answer they assembled was compersion. The term spread into the wider non-monogamous community through Ryam Nearing's Loving More magazine and conferences in the mid-1980s.

Definitions converge on the same idea: a felt sense of warmth or vicarious joy when a partner is enjoying connection with someone else. Wikipedia's polyamory entry describes it as “an empathetic state of happiness and joy experienced when another individual experiences happiness and joy,” analogous to the joy parents feel at a child's wedding rather than a romantic mirror image of jealousy.

Inside the lifestyle, compersion is often discussed as a skill rather than a personality trait. Practitioners describe it as something that can grow with security, communication, and time, but also as a feeling that comes and goes scene by scene. Most experienced voices in the community caution against treating it as mandatory, since framing compersion as a moral requirement tends to push partners into performing emotions they do not actually have, which corrodes the trust the concept was meant to support.