Deciding my Major

What I want to do is something with graphic design or advertising. I am also into psychology. I think that I want to do a mix of both psychology and advertising, I think it is called business psychology. If you don't know what business psychology is, then I will tell you. Business psychology is basically product placement in a store. A business psychologist will go into a company or store and tell the company where to place products to get the best benefit from them. For example, in a grocery store the products that are placed at eye level are researched to be the most purchased because consumers do not look high and low, so stores know this and they put the most expensive products on the eye level shelfs. This seems very interesting to me because of the mixture of psychology and design. If not that then I may want to do product design because I want to learn what attracts consumers to buy products, especially consumers of all ages. For example, babies or toddlers like to see bright colors, so designers of products will make there toy as bright as possible to attract the children. I am really interested in why consumers buy things, if its product placement, or product design. I am taking a design class right now and I am learning how colors effects a persons emotions and also how lines can produce emotions as well.
A. Lee