The pregnant person fallacy is a fallacious argument that discriminating against some property that an oppressed group holds disproportionately is not discrimination against that group.
For example, take discrimination against pregnant people, against short people, against people who are not at the top level of athletic performance or of strength, against people who wear skirts (in Anglosphere business culture), or against people who took time out of their career to raise children. Despite the fact that not all women and some men and non-binary people are affected by each of these discriminations, due to their disproportionate impact on women these examples likely are discrimination against women (in some cases in combination with discrimination against other oppressed groups).
Arguing that none of these examples is discrimination against women because nothing can be discrimination against women unless it is against every woman and no other person is the definition of the pregnant person fallacy.
In The Mismeasure of Woman, (pp. 119-121) Carol Tavris wrote about arguments that discrimination against pregnant women is not sexist. She cited examples of arguments that such rules don't discriminate against women, and thus aren't sexist; no, these arguments go, they just discriminate against pregnant people.
The fallacy is that it's no coincidence that a large majority of people who become pregnant are women, and thus laws and policies that apply to pregnant people are as wont to be influenced by sexism as policies that apply expressly to women. (The existence of trans men and genderqueer people who become pregnant does not negate the overall point.)
In general, then, one silencing tactic for discussions about sexism is: "But $FOO doesn't discriminate against women! It only discriminates against people who have property $BAR." If it so happens that, for example, 50% of women have property $BAR while only 0.05% of men do, the person doing the silencing deems this disparity an irrelevant matter of statistics, rather than evidence that sexism may be involved in $FOO. In reality, $BAR may well be a proxy for gender that people holding power use to discriminate against women tacitly while easily dodging accusations of sexism, and the adoption of this proxy may be unintentional or intentional.
- It's common for white Americans to declare that there is no racism in America, and that there is only classism. This argument is an example of the pregnant person fallacy, because it reflects willful ignorance of racial disparities in socioeconomic status.
- Someone who points out that the blackboards in a math or science building are placed at an ideal height for an average-sized adult man, reflecting architectural sexism that embodies the assumption that a math or science instructor will be a cissexual man, may be silenced with the rejoinder "but it discriminates against short men, too!"
- In the US, the state of Texas has a different age of consent for sex between two people of the same sex, and two people of a different sex, with a higher age of consent for sex perceived as same-sex. Claiming that this disparity was due to antipathy towards anal sex, rather than antipathy towards gay men, lesbians, and bisexuals, would be an example of the pregnant person fallacy, since antipathy towards certain sex acts is linked with homophobia.
- During the controversy over sexual imagery in the CouchDB talk at the 2009 Golden Gate Ruby Conference, a common response to the assertion made by women and allies that such imagery creates a hostile environment for women was, "It's not about women; the talk was offensive to anyone with good taste." While men may indeed be uncomfortable with or offended by sexual imagery in a professional context, to deny that the talk created an environment that was especially hostile to women is to deny that a greater percentage of women than of men associate the presence of unwelcome sexual images with a threat to their physical safety.