"The tactics applied more often to harassment of women are more varied, longer-lasting and often designed to provoke fear," she said.
"In many cases, the harassment more often aimed at women has further-reaching repercussions - personal, financial and professional," Lenhart said.
Women who said they faced online harassment were "almost three times as likely as men to say the harassment made them feel scared," according to the study - and twice as likely to say it made them feel worried.
Men were more likely to say they weren't bothered by harassing behavior - and were less likely to describe what they experienced as harassment at all.
Of the people who said they went through some of the harassing behavior asked about in the survey, just 40 per cent of men thought their experiences counted as "harassment or abuse" compared with 50 per cent of women.
Some of that gap is because of the different types of behavior men and women experience online. But it's also connected to who has power in our culture at large, according to Lenhart.
"If you generally find yourself in a powerful subject position in your life, these experiences of harassment and abuse do not appear to have the same impact as they do on those who are more often subject to the power and control of others," she said.