CLIFFSIDE PARK, N.J., Sept. 13 — Son Man Soon, 93, spends her afternoons at the Long Life Adult Day Care Center watching a handful of women her age learn line dances, or singing along, karaoke-style, with Korean words on a large television screen. Some of her peers play mah-jongg or pool, some knit, and later, they enjoy meals of soybean sprout soup and kimchi.

“Around here, these people, they don’t die,” Ms. Soon said, laughing. She lives by herself in a nearby apartment, and, aside from occasional trouble with her legs, considers herself healthy.

Around here, in Bergen County, Harvard researchers have found a surprising pocket of longevity. Asian women here live longer than any other ethnic subgroup of people in the nation, according to federal statistics. Their average lifespan is 91.1 years, compared with 77.5 for the general population, 86.7 for Asian women nationally, and about 80 years for Bergen County as a whole, a figure that places it first in the Northeast.

“I believe they got better medications and food, and they’re comfortable,” Ms. Soon said through a translator, referring to the Korean women in their 80’s and 90’s surrounding her. “Their kids are all well educated.”