Semantic Priming - using words to give a nudge

Mark Smith tells us that we are given a nudge in many ways throughout our daily lives.  For example, he says that supermarkets place their fruit and veg at the front of the shop in order to encourage us to buy healthy, then compensate for this with junk food.  Of greater interest is the notion of semantic priming.  I love words, and I believe they should be the bedrock of communication.  I am interested then in the study that suggests that using words to describe old age and youth can affect our behaviour accordingly; we take on the attributes of old age and youth, depending on which we are describing.