By RONI CARYN RABIN

Scientists call it the “Hispanic paradox”: despite high rates of poverty and relatively low rates of health insurance, Hispanics in the United States tend to outlive African-Americans and non-Hispanic whites.

A government report last week provided statistical confirmation of the phenomenon. It found that as of 2006, the life expectancy for Hispanics at birth was 80.6 years, 2.5 years more than for non-Hispanic whites and almost 8 years longer than for blacks.

The finding is all the more surprising because Hispanics have lower median family incomes and a higher poverty rate than whites, and are less likely than whites to have a college education — all factors associated with better health. They also have high rates of obesity and diabetes.

So what accounts for the paradox? The report’s author, Elizabeth Arias of the National Center for Health Statistics, speculated that the longer life expectancy might have to do with cultural factors, including close social and family networks and low rates of smoking.

“One hypothesis,” Dr. Arias said, “is that these serve as protective factors that mitigate the negative effects of poverty or underemployment or lack of health care.”