From Sojourner Truth onward, some women argued that a feminism built on the experience of white, middle-class women missed much of what other women faced. In 1989 that argument received a name.

Crenshaw and intersectionality

The legal scholar Kimberlé Crenshaw introduced the term intersectionality in a 1989 article in the University of Chicago Legal Forum. She examined how antidiscrimination law handled claims by Black women. Her key case was DeGraffenreid v. General Motors (1976). Five Black women argued that the company's seniority-based layoffs discriminated against Black women in particular, since the company had not hired Black women before 1964. The court refused to treat Black women as a distinct group. It rejected the sex discrimination claim because GM had hired women before 1964 (white women, mostly in office jobs), and it suggested folding the race claim into a separate case about Black workers, whom GM had hired (Black men, in factory jobs). Split into a sex claim and a race claim, the women's claim fell between the two.

Crenshaw argued, in paraphrase, that treating race and sex as separate categories made those at their intersection invisible, both in law and in feminist and antiracist politics. She used the image of a traffic intersection: a person standing there can be hit by traffic coming from more than one direction, and the harm may not be traceable to any single road.

The idea had earlier roots. In A Voice from the South (1892), Anna Julia Cooper wrote about the double burden of Black women. In 1977 the Combahee River Collective, a group of Black feminists in Boston, issued a statement describing interlocking systems of oppression based on race, sex, class and sexuality.

Uses and criticisms

Today the term is used broadly, to include class, disability, religion and other factors. Supporters see it as a tool for noticing who policies and movements overlook. Critics argue that in popular use it can become a ranking of grievances that divides people, that it can stress group identity over shared citizenship or class, and that its claims can be hard to test. Crenshaw has said that some popular uses stray from her original legal argument.

The third wave

In the early 1990s a younger generation began calling itself the third wave; the writer Rebecca Walker used the phrase in a 1992 essay titled “Becoming the Third Wave.” Third-wave feminists emphasized diversity among women, individual choice, and reclaiming femininity and sexuality that some second-wave writers had criticized. They were wary of any single definition of feminism, drew on global and queer perspectives, and used music, zines and popular culture, as in the riot grrrl punk scene. Critics, including some older feminists, argued that “choice feminism” risked treating any choice a woman made as feminist and losing sight of collective goals.

Internationally, the 1979 UN Convention on the Elimination of All Forms of Discrimination against Women and the 1995 Beijing World Conference on Women made women's rights a standard part of the human rights agenda.

The fourth wave

From around 2012, a fourth wave emerged online, using social media to share experiences and organize, especially against sexual harassment and violence. The phrase “Me Too” had been used by the activist Tarana Burke since 2006; in October 2017 it spread as a hashtag after allegations against a film producer, with millions of posts worldwide. Supporters credit the movement with exposing widespread abuse and changing workplace norms. Critics, including some feminists, raised concerns about due process, about lumping serious crimes with lesser misconduct, and about online pile-ons in which accusations were treated as proven.

Worked example: testing for intersectional gaps

Imagine a mid-sized company proud of its diversity record. It reports that 45 percent of its managers are women and 20 percent are Black, close to the makeup of its workforce. The board concludes it has no problem.

An analyst looks more closely and breaks the numbers down further. Nearly all the women managers are white, and nearly all the Black managers are men. Black women make up 12 percent of the workforce but only 1 percent of managers. Measured separately by sex and by race, the company looks fine. Measured at the intersection, a large gap appears. This is the DeGraffenreid problem in a modern setting.

What might explain the gap? The analyst considers possibilities that can be checked: are Black women less often recommended for training programs? Do they leave sooner, and if so, what do exit interviews say? Are promotions decided by informal networks they are excluded from? Each explanation suggests different solutions, and some explanations might turn out to be wrong.

Now apply the critics' cautions. Breaking groups into ever smaller subgroups can produce numbers too small to mean much, and every split can reveal some gap by chance. A sensible approach uses intersectional analysis to find possible problems, then tests them carefully before acting. It also asks whether a fix helps everyone facing the barrier, such as making promotion criteria clear and public, rather than only one group. Used this way, intersectionality is a practical tool for seeing what simpler measures miss, without turning into a contest over who is most disadvantaged.