What were the most significant theoretical understandings of the human condition

What were the most significant theoretical understandings of the human
condition identified by the humanistic movement of psychology in the United
States? Who were the primary standard bearers of these theories? Why were these
theories significant in the advancement of the humanistic movement?
Options for
Sources:
Felder, A. J., Aten, H. M., Neudeck, J.
A., Shiomi-Chen, J., & Robbins, B. D. (2014). Mindfulness at the heart of
existential-phenomenology and humanistic psychology: A century of contemplation
and elaboration. Humanistic
Psychologist, 42(1), 6–23.
McDonald, M., & Wearing, S. (2013). A reconceptualization of the self in
humanistic psychology: Heidegger, Foucault and the sociocultural turn. Journal
of Phenomenological Psychology, 44(1), 37–59.