I talk to Sylvia Hewlett about her research on corporate underappreciation of black executives and my mind goes back to the 1934 film version of Fannie Hurst's "Imitation of Life."

Not the part where "Miss Bea" (Claudette Colbert) markets the secret pancake recipe of her black friend "Delilah" (Louise Beavers) for their (evenly?) shared profit. No, I'm thinking of the poignant episode at the end, when Delilah dies, after spending years living with Miss Bea, after they have become mutually dependent, after they've raised their daughters together. The warm and sensitive Miss Bea is flabbergasted to learn, at the funeral, that her friend has scores of other friends and family members, a respected place in her church and community -- virtually an entire life -- that had been utterly unknown to her.

Why didn't she know?

That's the question Hewlett and fellow researchers Carolyn Buck Luce and Cornel West try to answer in a report in the Harvard Business Review -- except now Delilah is a corporate executive working for Miss Bea, who still knows far less than she imagines about her friend.

The report -- "Leadership in Your Midst: Tapping the Hidden Strengths of Minority Executives" -- argues that minority executives are often undervalued because their non-work activities are unknown or unappreciated by corporate management.

It is arguable that managers don't know about the outside activities of most of their employees. Still, says Hewlett, that lack of knowledge redounds to the special disadvantage of minorities -- for two reasons.

"First, minority professionals tend to be more engaged with community and with outside roles and responsibilities than are white professionals," she said in an interview from her New York office.

"Second, though, what they are engaged with is different. White involvement might be with formal civic organizations -- United Way, symphony boards, the standard community roles." Blacks, she said, tend to be involved in church leadership, in leadership of fraternal organizations and in efforts to "give back" to the often-needy communities they come from.

That's all very nice, of course, but why should corporate management care?

"Because they understand that leadership skills are developed in a variety of venues," Hewlett says. "Read the official bios of corporate leaders, and you'll find that they almost always list civic activities and community leadership roles. They know these roles are valued by their companies.

"I talked with an African American woman who works at a major company. She is extremely active in her Baptist congregation, has led in reorganizing her denomination's social outreach programs in her state. She took on a five-year program to transform the social ministry. And she has shared none of this at work."

Why? "She belonged to the 'wrong' church -- not the kind of church her company's leadership belonged to -- and she feared that knowledge of the extent of her activities on behalf of her faith community would underscore the fact that she's 'different' or somehow feed a negative stereotype," says Hewlett.

She cited the example of another woman who became an amateur actor, thinking it would enhance her presentation skills. "The first time she decided to talk about her theatrical experience on the job, her white boss told her that he had expected some 'weird actress type' to walk in." Instead of the experience being a boost for her career, it became something to neutralize.

The article, based on a survey of 1,601 college-educated professionals (including 1,001 African American, Hispanic and Asian women) is not exclusively about outside activities. Many of the women said they felt implied pressure to look, sound and act like white male executives; or worried that their dress might be viewed as "too ethnic"; or even feared that their animated hand gestures might be perceived as somehow inappropriate.

But the differential value assigned to outside activities is especially intriguing.

The authors are part of a "hidden brain drain" task force that is trying to help 31 companies learn to see the overlooked strengths of their minority professionals -- to "re-imagine what we mean by inclusion."

"What we are trying to get them to understand is their tendency to look at the world through a white lens," Hewlett explains.

For instance: Colin Powell's extraprofessional work with America's Promise is the sort of thing that corporations automatically value, she said. "But when you look at the work of caring in the lives of many minority professionals, you are likely to find a focus on the nuclear and extended family -- family sometimes defined to include stepchildren, godchildren, and 'nieces' and 'nephews' with no blood ties.

"This isn't the sort of thing people feel encouraged to include in their resumes, but that doesn't mean it's not important."