I saw the Spanish cavalry at La Roque it was lovely
Pleasantness of an odor is attributed mainly to associative learning: The odor acquires the hedonic value of the (emotional) context in which the odor is first experienced. Associative learning demonstrably modifies the pleasantness of odors, particularly odors related to foods. Experimentally, classical conditioning paradigms (Pavlovian conditioning) have been shown to modify the responses to odors, not only in animals but also in humans (olfactory conditioning).
In olfactory conditioning an olfactory stimulus is the conditioned stimulus that has been paired with an unconditioned stimulus (e.g., taste). For instance, the pleasantness of odors with originally neutral hedonic value was improved after the odors were paired as few as three times with the pleasant unconditioned stimulus, sweet taste. This type of conditioning, where liking of a stimulus changes because the stimulus has been paired with another, positive or negative, stimulus is called evaluative conditioning.
Naturally occurring evaluative conditioning may be important also in modifying the pleasantness of a partner’s body odors (conditioned stimulus) that are encountered initially during affection and sexual intercourse (unconditioned stimulus), because the sexual experiences presumably provide strong, positive, emotional context.
Searches for human pheromones have focused on androstenes, androgen steroids occurring in apocrine secretions, for example, axillary (underarm) sweat, motivated by the fact that one of them, androstenone, functions as a sex pheromone in pigs. However, some 20–40% of adult humans, depending on age and sex, cannot smell androstenone, although their sense of smell is otherwise intact. To date, no convincing evidence exists to demonstrate that any single compound is able to function as a sexual attractant in humans, although several other types of pheromonal effects (e.g., kin recognition) have been observed.
While many studies have explored potential physiological and behavioral effects of the odors of androstenes, we asked a different question: Could an odor (conditioned stimulus) that is perceived during sexual intercourse gain hedonic value from the intercourse experience (presumably a pleasant unconditioned stimulus) through associative learning? While experimental challenges limit human studies of this kind, we approached the question by asking young adults, randomly sampled regarding the level of sexual experience and olfactory function, to rate the pleasantness of body-related (androstenone and isovaleric acid) and control odorants (chocolate, cinnamon, lemon, and turpentine). We compared the responses of participants with and without experience in sexual intercourse and hypothesized that those with intercourse experience would rate the pleasantness of the odor of androstenone higher than would those without such experience. […]
The results suggest that, among women, sexual experience may modify the pleasantness of the odor of androstenone.
