A couple of years ago I shared a tidbit that came through my inbox about hiring practices for women during World War II. The item had a tremendous amount of shock value and really did support the slogan, “You’ve come a long way, baby.”

So fast-forward to the early 1980s, when a newly hired Denise Butler was taken by her colleagues to the Petroleum Club in New Orleans, only to be turned away because women weren’t allowed in the club at the time.

Women may have had their own cigarette by then, but they certainly hadn’t achieved equal footing in the oil and gas industry.

Butler, of Shell, and Cindy Yielding of BP spoke at a recent Houston Geological Society luncheon about gender diversity in the workplace. I think the few men in the audience were a little scared at the reception they would get, but the speakers made it a point not to complain about their past treatment, alienate men, or insist that women should rule the world. Their concerns were more about the future — how does the industry continue to attract women into the geosciences, and more importantly, how do we keep them?

Yielding pointed out some of the basic differences between the way men and women work. Men have 6.5 times more “gray matter” in their brains, which makes them good at processing information. Women, on the other hand, have 10 times more “white matter,” which establishes connections to see and process patterns from disparate sources of information. This, in turn, makes men more likely to thrive in a hierarchical management structure typical of most businesses today, whereas women thrive in a “multiparty” organization model where all parts are interconnected.

The crux of the presentation was the percentage of women who remain in the industry today. The presenters identified several “waves” of women in geoscience. The first wave was the pioneers, who entered the industry anywhere from pre-1980 to the middle of that decade. Their mantra was, “Act like a man.” The next wave were the ones who survived layoffs during the 1980s and ’90s. Women who have entered in this decade tend to be more racially diverse, and women who are entering today are looking for more flexibility in their careers. The biggest question about this final group is, will they stay?

The criticality of this question becomes obvious when one looks at the demographic distribution at a major oil company (data was limited, but it can be supposed that many companies would offer a similar set of statistics). Yielding said that when she graduated in 1995, about 35 to 40% of her fellow geoscience graduates were women. But in 2009 that same age group makes up only about 10 to 15%. This can be attributed to a number of factors, including layoffs, volunteer packages, switching industries, a lack of inclusion in the workplace, an inhospitable work climate, and family priorities.

Yet a business case can definitely be made for having more women in management. Studies have indicated that companies with a higher percentage of women in management have a 35% return on equity over their male-dominated competitors and a 34% return to shareholders. Fortune 500 companies that have at least three women on their boards of directors enjoy a 73% return on sales, an 83% return on equity, and an astonishing 112% return on invested capital.

Butler continued the retention message by noting that companies start losing their women geoscientists 10 to 15 years into their careers. This is not just a waste of talent; it’s also bad for business, she said, since it costs between US $500,000 and $1 million per employee in the first five years of their employment once things like benefits, training, and mentoring are factored in.

“Forget the warm and fuzzy part — we can’t afford this,” she said. “It cripples the business.”

Age demographics also come into play, regardless of gender. “These graphs are real and will impact the workforce in the next 10 years,” she said. “We need to retain all geoscientists.”

Doing this will require increased flexibility on the part of management, as today’s recruits want rewarding careers; a fair and balanced workplace; job flexibility that doesn’t jeopardize career advancement, children, elder care, or significant life events; management that understands that “face time” doesn’t equate to work ethic; and recognition and remuneration that’s reflective of one’s seniority and work history.

Management can help by understanding why employees leave and attempting to change these things by not assuming that all women’s goals are the same, by understanding that employees’ goals change over time, and by supporting the initiatives your company already has in place while lobbying to add the ones you don’t.

“My personal view is that the energy industry is a tough business,” Butler said. “We’re all tough cookies. It’s one of the most exciting businesses I know of, and I want the next generation of women to have the same opportunities I’ve had.”