Pence is not the only powerful man in Washington who goes to great lengths to avoid the appearance of impropriety with the opposite sex. An anonymous survey of female Capitol Hill staffers conducted by National Journal in 2015 found that “several female aides reported that they have been barred from staffing their male bosses at evening events, driving alone with their congressman or senator, or even sitting down one-on-one in his office for fear that others would get the wrong impression.” One told the reporter Sarah Mimms that in 12 years working for her previous boss, he “never took a closed door meeting with me. ... This made sensitive and strategic discussions extremely difficult.”

Social-science research shows this practice extends beyond politics and into the business world, and it can hold women back from key advancement opportunities. A 2010 Harvard Business Review research report led by Sylvia Ann Hewlett, the president of the Center for Work-Life Policy think tank, found that many men avoid being sponsors—workplace advocates—for women “because sponsorship can be misconstrued as sexual interest.”

Hewlett’s surveys, interviews, and focus groups found that 64 percent of executive men are reluctant to have one-on-one meetings with junior women, and half of junior women avoid those meetings in turn. Perhaps as a result, 31 percent of women in her sample felt senior men weren’t willing to “spend their chips” on younger women in office political battles. What’s more, “30 percent of them noted that the sexual tension intrinsic to any one-on-one relationship with men made male sponsorship too difficult to be productive.”

And that’s too bad, because according to the Harvard study and some others, women prefer male sponsors, perceiving them to be better-connected and more powerful. And they’re right: According to some analyses, men hold more than 85 percent of top management positions in big companies.

Because of that, when men avoid professional relationships with women, even if for noble reasons, it actually hurts women in the end. “The research is irrefutable: Those with larger networks earn more money and get promoted faster. Because men typically dominate senior management, there’s evidence that the most valuable network members may be men,” wrote Kim Elsesser, a research scholar at the UCLA Center for the Study of Women, in the Los Angeles Times recently. “Without access to beneficial friendships and mentor relationships with executive men, women won’t be able to close the gender gap that exists in most professions.”

Re the Mike Pence quote: Trying to imagine what my career would look like if I’d refused to dine solo with male editors & interview subjects — Pamela Colloff (@pamelacolloff) March 30, 2017

Establishing cross-gender mentors, or even just office buddies, can be awkward. One study found that when mentors and their proteges are of different genders, they socialize less outside of work and their work relationships are harder to initiate because they worry others will misconstrue their friendliness as sexual interest. In a 2006 paper, Elsesser found that 75 percent of men in her sample worried about sexual harassment issues when interacting with woman at work, and 30 percent of participants had co-workers question them about the true motives behind a cross-gender friendship. In research Elsesser conducted for her recent book on the topic, some professional men and women told her they avoided dining with the opposite sex because they worried about the situation being misunderstood or didn’t want to upset their spouses. In psychology, this is known as the “audience challenge” to cross-gender friendships: People worry what their neighbors or co-workers are going to think.