Research shows that the quality, as well as the diversity, of relationships bolsters health. In one study, older adults who had satisfying relationships with their spouse or partner were less likely to suffer depression after stressful work events. In another study, adults with many different types of relationships were four times less likely to catch a cold than those with less diverse social circles.

How do family and friends benefit your health? One theory: A wide social circle serves as a buffer against the damaging effects of stress on the immune system. Family and friends also may help people cope with physical and emotional stress.