Mothers and matchmakers(媒人) have always known that not being married is a definite health hazard. But when a team of researchers from the University of California, San Francisco, reported a few weeks ago that middle-aged (中年的) men without wives were actually twice as likely to die during a 10-year span(全长) as men with wives, the espoused and the spouseless alike stopped to take notice. It was the kind of news that swept through offices and watering holes-and it made people feel smug(自鸣得意的) or anxious, depending on their circumstances. Now the researchers who conducted the study are trying to find out what accounted for(说明,解释) the dramatic differences in survival rates. The investigators, headed by UCSF associate professor of epidemiology arid biostatistics(生物统计学) Maradee A. Davis, had set out to examine the effect of various living arrangements on mortality. Because of the buffering social support marriage is known to provide, Davis and her colleagues fully expected to find that men and women dwelling alone fared(生活,进展) worst in survival rates. It came as some surprise, however, that in their study population, subjects who shared living quarters with people other than a spouse had the same lower survival rates as those who lived by themselves. 'The critical factor, 'Davis says, 'seems to be the presence of a spouse.' The lower survival rates for the spouseless were found primarily in men who were widowed, separated or divorced, rather than in those who had never been married. Davis and her colleagues have already eliminated certain health factors as causes of higher mortality by adjusting their data to discount the effects of smoking, alcohol consumption, obesity and lack of exercise. Now they will look more closely at a variety of other considerations, such as blood pressure, cholesterol levels and chronic illnesses. Sex roles: While many middle-aged men now know the difference between a cheese grater and a garlic press, nutrition may still account for some of the California study's findings. Previous research by Davis's team showed that unmarried men even if they lived with other people ate less healthy diets than married men. 'Traditional sex roles have meant that men aren't as well informed as women about nutritional shopping and food preparation. 'says Davis. Emotional and social factors probably also played a role in higher mortality among the spouseless men. The San Francisco researchers will examine a randomly selected subgroup of their study population for more detailed medical data, and they'll look at a trait(特征) they call 'general well-being. 'This focuses on subjectively reported feelings and moods, rather than specific psychological symptoms. The researchers will analyze questionnaires that asked how frequently the men felt worried, nervous or poorly rested. But the team will also look at the causes of death if the men without wives show higher rates of suicide or fatal accidents, it's likely that emotional stress contributed to(可助于, 促使)their higher mortality rate. Davis has already discovered that the married men reported a significantly higher level of well-being than those who weren't married. So perhaps the explanation for their longer survival isn't really so complicated. Because they are cared for by nurturing wives, they just plain feel happier than the other guys do. And what better reason than for staying alive? Environmental factors affect our health in important way.