Female physicists are significantly under-cited compared to their male counterparts, according to an analysis of more than a million physics research papers. Carried out by a team led by physicist and systems neuroscientist Dani Bassett from the University of Pennsylvania, the study found the gap is biggest in articles written by men citing papers in fields they are less familiar with (Nature Physics 18 1161).
Covering papers published between 1995 and 2020 across eight different sub-fields of physics, the researchers used a gender-identification service to categorize papers as either “man-authored” or “woman-authored” based on the first names of the first and last authors. Although this method does not always reflect a person’s identity accurately, the researchers argue it is appropriate in this context as citing authors are also likely to perceive gender from first names.
The researchers found that, overall, woman-authored papers are cited 3.17% less frequently than expected, while man-authored papers are cited 1.06% more frequently than expected, giving a total disparity of 4.23%. The difference varies between different sub-fields, with the greatest gender gap being in general physics journals and the smallest in astronomy and astrophysics.
Several other factors were found to influence the disparity, including what the researchers call “proximity” – the tendency to over-cite man-authored papers when the citing author is less familiar with the field they were citing. The gap is also larger when the citing papers are man-authored and when journals limit how many papers can be referenced.
Research by women shared less than work by male colleagues, study finds
Despite the proportion of woman-authored papers rising significantly over time, the study reports that the citation gap actually broadened slightly between 2009 and 2020. The researchers believe this could be a result of preconceptions about who works in a discipline.
“We refer to this mechanism colloquially as ‘citing like it’s 1995,’” Bassett told Physics World. “If an author built up a perception of the demographics of the field decades ago, but the demographics are steadily diversifying, then the citation gap will simply grow.”
The researchers hope their study will spark debate, given that physics lags many other sciences in gender equity and representation. Individual researchers can address inequity, the authors say, by informing themselves about the work of under-represented scholars or by including citation diversity statements in their papers. Journals, meanwhile, could increase the proportion of woman-authored papers they publish and remove limits on the lengths of references.
“Citation diversity – along the lines of gender, as well as race, ethnicity, and other characteristics – matters for the flourishing of our community,” says Bassett, “and for our potential to appeal to and support the best minds of the future.”