New research shows that consumers may react to these products with visceral disgust - which they may then transfer to usually desirable products - like cookies - if the two products touch each other on store shells or even in the shopping cart. That’s according to a study to appear in the May issue of the Journal of Marketing Research. For example, study subjects were less likely to accept the offers of a cookie, even an hour after they saw a package of cookies touching a box of sanitary napkins. The researchers point out that the behavior may have a sound instinctual basis - we probably naturally avoid foods that we think may have been in contact with germs or something else unhygienic. Transparent wrappers heightened the associative effect. Participants who saw rice cakes in clear wrapping touching a jar of lard estimated the cakes to have more fat in them than cakes in opaque packaging. Bottom line, manufacturers might want to pay even closer attention to packaging and retail sale shelf position.