In a series of studies, the researchers found not only that some products--trash bags, diapers, kitty litter, tampons--evoke a subconscious feeling of disgust even before they're used for their ultimate messy purposes, but they can also transfer their general ickiness to anything they come in contact with.
The idea that negative qualities can be passed by a touch has become hardwired, says Fitzsimons. (That applies to good qualities too, which is why touching a holy object or person is considered a way of acquiring a little holiness for oneself.) So he and Morales set out to see whether toilet paper and other products could psychologically contaminate food in a shopping basket.
Any food that touched something perceived to be disgusting became immediately less desirable itself, though all of the products were in their original wrapping. The appeal of the food fell even if the two products were merely close together; an inch seemed to be the critical distance, More irrationally still, the subjects were less comfortable with a transparent package than an opaque one, as if it somehow had greater power to leak contamination.
It's also part of a growing trend of applying science to supermarkets (see chart). Analysts who study shopping habits have already made some surprising discoveries about product placement. "Eye level," for example, used to mean, not surprisingly, "at the level of the eyes." But shoppers tend to keep their eyes aimed at cart level much of the time, making sure they aren't about to run over another customer. And because Americans read from left to right, shelf-stockers tend to put name brands like, say, Heinz, on the left side of the ketchup display, and the lesser known, more profitable in-house brand on the right.
the whole article is here
It's very interesting since I find myself in the supermarket when i put things in the bags I try to keep the toilet paper alone in a separate bag I never knew why but I was doing it subconsciously and now thinking about it yes I would always try to not take anything I see someone holding before me like like if I want a can of Pepsi and someone just warped his hand around it and put it back in the fridge I wont take that one but another one , I think of it as matter of not healthy more than Ewww but after all the Pepsi alone unhealthy and at least 10 people touched before it got to me so in the end should we make a bag for the can so when you take it you throw the bag and open the can cos the can only protects whats in it but what protects the can itself .
this reminds me of bazeen, isn't it cool to eat it with someone with green color under his nails :P
in the end as they say what doesn't kill you makes you stronger or as we say in Libyan
اللي ما يقتل يسمن