Incel is an academic sociological term that is short for involuntary celibacy, a common adverse life circumstance. An analogy many incels often find elucidating would be comparing the state of lifelong inceldom to other common adverse life circumstances, such as poverty. Inceldom was recognized in academia, as a sociological phenomenon, in the landmark Donnelly Study, published in 2001. Many further peer-reviewed academic papers have since been written, portraying involuntary celibacy as a (mostly) adverse life circumstance rather than exclusively describing a specific internet subculture.

Academic researchers who have examined involuntary celibacy (though not all use that exact term) include: Denise Donnelly, Elizabeth Burgess, Laura Carpenter, Theodor F Cohen, and Menelaos Apostalou. Brian Gilmartin also conducted extensive research into the closely linked concept of love shyness. The initial study explicitly dealing with the topic of involuntary celibacy, the Donnelly Study, defined incels as all adults who fail to find a sexual partner for six months, despite their desire for one. However, among self-identified incels, there is often fervent disagreement about the exact definition.

This wiki takes the stance, in agreement with the early academic research into the topic, that incel is not a movement or a community, but a gender-neutral life circumstance (though it can indeed be argued that it is more common among specific demographics than others). Incels (both self-identified and not) are highly diverse politically, racially, religiously, and socioeconomically.

Online communities of self-described incels are also extremely diverse in terms of racial/ethnic make-up, political beliefs, and user's views on the ultimate causes of involuntary celibacy and the possible solutions proposed to alleviate this circumstance. This user diversity in origin and ideology is precisely what one would expect for communities organized around a life circumstance, rather than any concrete ideology.

Philosophies like the blackpill, political parties like Incel Party and the ALF, or subcultures like 4chan/imageboard culture do not represent all incels. Involuntarily celibacy is also by no means uncommon, either throughout history or in contemporary societies. For instance, among American millennials, 15-30% are incels, roughly 51% do not have a steady partner, roughly 30% are often or always lonely, and roughly 22% have no friends.

Current prominent incel forums are: Incels.co, love-shy.net, Incelswithouthate, and Foreveralone. No mass-shooters or other criminals identified by the media as 'incels,' or that self-described as such, have been members of any online community explicitly devoted to involuntary celibacy. Some of these individuals had used online communities such as 4chan and PUAhate, which were not/are not communities dedicated to involuntarily celibacy.