Longevity is making four-generational families commonplace. You see it at family reunions and special celebrations honoring long-lived family members. And inevitably, four generations are showing up in the workplace, as more people 50 and older choose to keep working longer, often among those young enough to be their grandchildren.

How well (or poorly) we will get along is the subject of a new book, How to Get Radio Babies, Boomers, Gen Xers, and Gen Yers to Work Together and Achieve More (Career Press, 2007) by Robin Throckmorton and Linda Gravett, based on a three-year study of workers from each age group.

Here’s how the authors see the generational divisions:

RADIO BABIES, BORN 1930 TO 1945
Background: Children who remember the Depression and/or World War II, appreciate employment and career continuity.

Common characteristics: Strong work ethic, extensive job experience. Often perceived as frail or inflexible.

Comments: “People are sometimes afraid of radio babies for health reasons. But radio babies want people to recognize that their bodies and brains still work. Those hiring people between 60 and 80 tell us they’re the most productive workers they have.”

BABY BOOMERS, BORN 1946 TO 1964
Background: Boomers grew up with post-World War II prosperity and TV; entered the work force when “career path” meant a single company ladder to climb.

Common characteristics: Hard workers, experienced and loyal. Sometimes seen as “stuck in their ways.”

Comments: “A lot of people are reluctant to hire boomers, thinking they’ll retire soon,” Trockmorton says. [But] They want to keep going. They want a better work-life balance. And their second career is often much different than the first one.”

GENERATION X, BORN 1965 TO 1976
Background: Latchkey kids, often from dual-income homes. Entered the work force at the dawn of the Computer Age.

Common characteristics: Independent, flexible, technologically diverse. Can be perceived as self-absorbed or disloyal.

Comments: “This is the first latchkey generation, so they’re very used to surviving on their own. They change jobs more often, so they put less stock in company loyalty. So, they can be seen (by elders) as impatient with their careers.”

GENERATION Y, BORN 1977 TO 1990
Background: Raised in a fast-paced, violence- and media-saturated, technologically booming world.

Strengths: Energetic, innovative. Can be viewed as arrogant or defiant.

Stereotype: “Gen Y’s are sometimes called ‘Gen Why?’ because they question everything. They look for the value in what they do, and are less inclined to confer respect upon someone because of a title.”

Given the differences in work attitudes, e.g. Radio Babies are famously ‘loyal,’ with a strong work ethic, vs. the Gen Y’s ‘what’s in it for me’ approach to work, the best strategy is “reverse mentoring,’” says Throckmorton. “Each group draws from the other’s wisdom. Boomers and radio babies know how things get done, and have the experience that comes from years inside the system. Generation Xers and Gen Y’s have a lot of new ideas and technological expertise. And those born on the cusp of each generation are vital because they communicate well with both sides. It does work, and we found that the generations born furthest apart have the most to teach one another.”

None of this will be news for you grandparents or Experience Corps mentors out there, of course.