What are the ingredients of a good relationship? Trust? Communication? Compromise? How about a sense of smell? When researchers in the United Kingdom surveyed almost 500 people with anosmia (the loss of sense of smell), more than 50 percent of them reported feeling isolated, and blamed their relationship troubles on their affliction. Smell is important in social bonding, says psychologist Pamela Dalton, at the Monell Chemical Senses Center, in Philadelphia. When a mom smells her newborn baby, the scent activates brain regions associated with nurturing behavior. Smells might also trigger brain activity linked with affection, compassion, or romantic love. Jeff and Anthony give this story the sniff test.