Balance theory, as used in psychology, is basically a concept on attitude change. It was proposed by Fritz Heider and it suggests that a "cognitive consistency motive" is a drive towards psychological balance. Cognitive consistency holds that humans have a deep need to maintain their beliefs and values over time. This can be exhibited by young adults who give up their teenage "rebellion" and return to the value system that they were raised with. Marketing people in the business have co-opted this theory by realizing that using popular celebrities to endorse products will likely make people view such brands more positively. Likewise, if some consumers already dislike the product being advertised, they will tend to dislike the endorser.