“Symptoms” of well-understood brain activity are clearly established via rewards and experience-dependent conditioned preferences that depend on hormonal changes driven by the effects of odors. Food odors and social odors elicit these “symptoms” of activity
Peer-reviewed journal articles detail the effects of natural odor from women on hormone levels in men, which are linked to behavior. Pheromone-enhanced fragrance products enhance the natural odor of women and can enhance attraction.
The molecular mechanisms of bacterial conjugation are lovingly extended to marital love, philosophically and biochemically.