Interpersonal interactions are primarily mediated through vision. However, crucial information concerning other individuals is also captured through different senses. New evidence suggests that body odors can implicitly initiate, filter, and guide the integrated perceptions that characterize real human impressions. Human body-odor processing helps rapidly differentiate kin from friends and friends from foes, as well as identify potential threats or increase alertness to the proximity of strangers, thereby guiding social preference. Body odors, which are potent sources of discriminative, affective, and motor knowledge, elicit neural activity partly or exclusively outside the primary olfactory cortices in the brain areas responsible for the processing of social information, which are activated by equivalent visual signals. Body odors, which can act as an authenticator of truth and are reliably invoked to shape social relations, require us to revise our view of the traditional body-communication models.