Researchers at the University of Texas, Austin, analyzed more than 400 publicity images for local broadcast journalists and found that 95.8 percent of female anchors and reporters had smooth hair. About two-thirds had short or medium-length cuts. Nearly half of the women were blond. Zero had gray hair. Just one black woman in the UT study sample wore her natural curls.

The style standards are a result of longstanding requirements that female reporters not only do their jobs, but “fulfill larger audience expectations of what women are supposed to look like,” says Mary Angela Bock, a UT assistant professor and lead author of the study. That ideal look “is stereotypically heteronormative, not overly sexy, and predictable.”

Sometimes, anchors’ contracts even go as far as explicitly preventing women from changing their appearance without a manager’s approval. Stations frequently hire consultants to help increase viewership, and they make recommendations on hairstyles in addition to news segments and set design.