Sociologists have consistently shown that the death of a spouse significantly increases the chances of the surviving partner’s death. But a recent Harvard study suggests that African-Americans do not experience this well-known “widowhood effect.”

The study, conducted by Felix V. Elwert, a doctoral candidate in sociology, and Dr. Nicholas A. Christakis, a professor at Harvard Medical School, looked at trends among 400,000 married couples over the age of 67.

The researchers found that white men are 18 percent more likely to die following the death of a wife, and that widowed white women are 16 percent more likely to die than their still-married counterparts.

By contrast, no widowhood effect whatsoever was found for black widows or widowers. This came as a surprise to the researchers. “While we expected the direction of this trend, we certainly did not expect to find no effect,” Elwert said. “We were surprised by how dramatic the results were.”

Although the causes for the racial discrepancy have not yet been studied, Elwert believes the difference arises from social context.

“Spouses are the first—and evidence suggests the most important—instance of medical care,” Elwert said. “They tend to be the primary caregivers for each other, and watch that their partners eat, sleep, and remember to take their medication.”

Black widows and widowers are more likely to have a support network available, and may therefore be less affected by a spouse’s death, Elwert said. Twenty percent of elderly single whites live with family members, compared to 40 percent of elderly black singles.

African-Americans are also statistically more likely to attend church and be active in their religious community.

In addition to the spiritual resources a church may provide, Elwert emphasized that the church also “links them to other members of the congregation and church infrastructure.” With more people looking out for their health, black widows and widowers may be better able to cope with the loss of their primary caregiver.

For husbands in interracial marriages, Elwert and Christakis found that the wife’s race played the deciding role. A white husband who lost his black wife experienced no widowhood effect, while a black husband who survived his white wife was more likely to die sooner.

“Women help the health of husbands by providing social connections,” Christakis explained, noting that a woman’s family and friends play a role in aiding her surviving husband after her death.

Christakis suggests that African-Americans tend to have a stronger kinship network; thus, a black woman’s family is more likely to take care of her surviving husband—regardless of his race—than a white woman’s family.

The study was conducted using the Medicare claims database, a widely used resource for sociologists. Elwert was able to control for health history as well as age, poverty status, and residential context. He chose to focus on elderly couples because 74 percent of Americans die after the age of 65, and most earlier studies of the widowhood effect have focused on younger couples.

Elwert said he intends to continue his research on race and the widowhood effect by looking at specific causes of death. Christakis is also currently studying the relationship between illness in one partner and death in the other. Although his work focuses on medical issues, Christakis said his ultimate goal is to gain insight into social relationships such as a spouse’s role as caregiver.