Outside of psychoanalytic and behaviorism theories, there is another factor that drives actions and behaviors; the desire to succeed and live a positive life. Two movements aimed to focus more on the positive experiences and thoughts that drive behavior than the negative ones that Freud focused on. (Cervone & Pervin, 2019) The Human potential movement looks at the potential of a human being and their drive to be and do good. The positive psychology movement aimed to use all people both those suffering from psychological issues and those that do not to create an understanding of how positive attitudes, behaviors, and feelings affect development.
Existentialism is a theory that there are factors such as religion, death, or phenomena that exists, but cannot be fully explained or understood, it relies on faith. (Cervone & Pervin, 2019) One aspect of existentialism is the view of the individual as a variable that only plays a small role in development but is defined to have free will and is unique. Within this view it is understood that each individual experience es things differently than all others and therefore actions and behaviors derived from these experiences are different.
These two theories are related because they identify that positivity and potential are key factors in psychology. In addition, not all things need to be explained. Positive outlooks and hope are found within individuals and religion, for example. With unknown origin, hope and positivity help to guide humanistic strengths and aid in survival. It is also interesting to examine the will to live in the face of imminent death that is also addressed with existentialism. Positive psychology addresses this with quality of life, positive mental attitude that provides enjoyable progress and development until death.
Cervone, D., & Pervin, L. A. (2019). Personality: Theory and research (14th ed.). Wiley.