According to the National Student Clearninghouse Research Center, the proportion of women earning undergraduate degrees in computer science fell from 37 percent in 1984 to just 18 percent in 2014.
Girls start making decisions about pursuing science and technology as far back as kindergarten, said ISC(2) Foundation's Franz.
"And something happens around middle school where girls get less interested in STEM topics," she said. "We know this from all kinds of data that's been studied."
Franz suggested that one explanation is that people are either interested in working with people, or in working with things.
Law and medicine, for example, are both extremely demanding careers that have no problems attracting women.
"These are jobs that are perceived to be around people," she said.
Technology needs a major rebranding, she said.
"Our focus seems to be on things," she said. "We're trying to secure things. When you talk to young women, they don't like a lot of the language around capture the flag competitions because they're all about things. About war."
But that's not what attracts women to cybersecurity, she said.
"When we ask younger women what makes them interested in the job, it's that they want to protect people," she said. "I think there needs to be a branding shift that needs to happen in the industry."
There's a whole generation growing up that is looking for more purpose in their careers, said Booz Allen's Messer.
This past summer, Booz Allen launched a new initiative, STEM Girls 4 Social Good. The kickoff project, a partnership with Girls, Inc. was a week-long camp where 40 girls investigated the problem of human trafficking by learning data science techniques.
"The idea is that we're protecting people, protecting the community, protecting the nation," Messer said. "And young women were interested. If we could pivot and talk about cyber like this, we could get more women -- and more young men -- focused on this field."
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