Self-deception is not a new cultural phenomenon, but it has always been popular. Self-deception takes many forms. Some kinds are harmless, such as the almost universal one of thinking that one is more attractive than one actually is. Others can be devastating, such as thinking that one is, for example, thinking that one is obese when actually he or she is seriously underweight. Interestingly, both of these conditions have to do with self image. As a matter of fact, many kinds of self-deception have to do with self image.
There are other kinds as well. In many of those cases it is not just an individual having deceptive thoughts herself or himself, but rather is encouraged to cleave to ideas that the individual probably deep down believes not to be true. This is the basis of the idea of propaganda, when ideas are planted by outside sources. There is one big movement that is current and we shall talk about it at some length.