Scientific studies of subliminal messages has thus far shown little to no effect on the behavior. It is considered to be an idea but scientifically sleeping, it does not really work. It is an idea that comes under the domain of psychology.
Psychology is considered as the science that which deals with the behavior and the thought of the mind, which includes both the unconscious and conscious aspect of the human mind. It is an academic field which requires extensive study. It falls under the domain of social science, aiming to understand the minds of people from a much more logical perspective.