A self fulfilling prophecy is a "prediction that causes itself to be true, due to the positive feedback between the belief and behavior."
This is a major hurdle for many with hair loss or beginning to have hair loss to overcome. Many believe that when they start losing hair, there is nothing that can be done. Often, they draw this experience from their personal life and from older people they have met with thinning hair or who are bald and think nothing works.
Many times, these same people google the terms and end up with confirmation bias.
The world has changed quite a bit since that era, with advancements in technology and science creating possibilities that are radically different than what was created in the past.