Age bias can be subtle — a whispered comment, a snide dig, an errant thought. Or it can show up in more overt behaviors — a forgotten meeting invite, a blatant preference for a younger colleague or even hiring discrimination.

Battling stereotypes

By 2022, 25% of the American workforce is estimated to be comprised of workers age 55 and older, according to the Bureau of Labor Statistics . But claims of age-based discrimination are already on the rise, says Michael North, assistant professor of management and organizations at New York University. Comparing the number of age discrimination complaints filed to the EEOC in 1999 to the number of claims now shows that the problem isn't going away.

This tension in modern workplaces, North says, often involves younger employees viewing older employees as overly aggressive, or selfishly refusing to step down from the C-suite and leadership roles.

The stereotypical version of this kind of older worker — who continues to work past retirement age, sowing discord among younger employees who covet the senior position — is usually male. Part of that stereotype stems from a dearth of older women in senior roles.

"One thing we're really seeing is a lot of dominant older men people think aren't willing to step aside, and you see resource constraints with millennials trying to get jobs, and we're thinking of male CEOs refusing to relinquish power — so I think the exemplars are men," says Ashley Martin, an assistant professor of organizational behavior at Stanford Graduate School of Business. "So when people harbor this age bias, they're thinking 'These men need to get out of the way.' And women are forgotten — which allows them to escape."

The 'intersectional escape'

Throughout their careers, younger women face many known biases in the workplace. They've historically wrestled with institutionalized sexism and are often "mommy tracked" when they have children. They walk a fine line when it comes to monitoring their own appearance, taking care to not appear too assertive or, on the flip side, too docile. But as they age, women tend to command more respect, while men appear to lose some.

This "intersectional escape," the phenomenon by which older women seem to escape age-based penalties, is actually rooted in sexism.

Younger employees perceive older women as less of a threat to their own careers. They're also more likely to view older, dominant women as maternal or caring, even if they behave in an assertive way. But these same employees instead see older men as overly aggressive and hostile to younger workers' success.

"They can escape backlash and we do see it in organizations: with time, older women are powerful women," Martin says.

There's still a lot of room for further research in this area, North and Martin say, especially in examining how these dynamics affect people of different races, backgrounds and other identities.

But for the time being, Martin recommends human resources departments consider the obstacles that can crop up on employees' career paths. Not just in terms of age, but in terms of life and career stage. The needs of working mothers, for example, are different from the needs of brand-new employees, or older employees returning to work.

"Women are not a monolithic category, and a lot of the diversity policies we're putting in place are monolithic," she says. "To assume all your female employees are having the same experience really undermines the ability of women to have their own experiences."