When the scent of a fragrant product triggers a fond memory that a customer holds, it is more likely to be a hit. So says Rachel Herz of Brown University, and Haruko Sugiyama and colleagues at the Kao Corporation in Japan and the US, who conducted a study now published in Springer's journal Chemosensory Perception. Its results indicate how a product's scent often evokes personal emotional memories and influences its appeals to customers.

Herz and colleagues set out to test how odor-evoked memories influence customers' perceptions of a product, as this has never been done before. Such so-called "Proustian memories" are usually formed early in life and are thought of less frequently than recollections elicited by visual or verbal cues.. Odor-evoked memories are also distinctly more emotional and evocative. They bring one back to the feeling of being at the original long forgotten event much more than memories triggered by any other of our senses do.

Samples of four scented body lotions were sent to 271 American women between the ages of 22 and 31 years old. Before starting to use these for a week, the women completed an initial online survey. They rated the lotion fragrances for pleasantness, intensity, familiarity, uniqueness and the degree to which these elicited personal memories. In a post-survey the participants rated how much they liked the lotions.

It was found that lotion fragrances that smelled pleasant and which evoked potent personal emotional memories were preferred. These are judged to be superior in many ways to the same lotion whose scent is equally pleasant, but did not trigger any recollections. The degree to which the fragrance evokes a Proustian memory for a given person determines how much a lotion is liked, and how highly its performance is rated. The more potent the memory that the fragrance triggered, the better the chances are that the lotion will be held in high regard.

"A scent's ability to elicit personal memories is more important than mere positive hedonics and how pleasant it smells," says Herz.

The researchers also say the findings highlight the individualized nature of Proustian-related fragrances, and how the effect of a scent will differ from person to person. Such idiosyncrasies abound because smell-related perception is largely determined by prior learning and personal history.

Knowledge about a given culture can help product developers predict the degree to which a specific fragrance will elicit certain scent associations. For example, in North America and Europe orangey-citrus scents are perceived as happy and calming, whereas jasmine is associated with a positive and relaxed mood in Japan. Having cross-cultural knowledge about when people from different regions first experience various scents may also help to develop products whose scents are most likely to elicit odor-related memories.