The first, and one of the most influential has been the psychoanalytic perspective, first championed by our coke-loving, cigar-chewing friend, Sigmund Freud.
心理学百科 The Psychology Book (Big Ideas Simply Explained)
The psychoanalytic theory of Freud gave an account of psychosexual development in children, and behaviorism explained the mechanics of the learning process.
Critics have pointed out that psychoanalytic interpretations aren't easy to prove or disprove, which is a problem when you're trying to take the scientific approach.
医学百科 The Medicine Book (Big Ideas Simply Explained)
The Freud Museum in Hampstead, London, housed in Freud's last home, includes his original psychoanalytic couch, preserved in the study where he treated his patients.
Much of the basic understanding of the effects of supportive psychotherapy as well as the techniques involved derives from the psychoanalytic perspective on mental functioning.
So, psychoanalytic and humanistic theories of personality were and are incredibly influential, even if one was a little sorted, and the other, a little sunshine and rainbows.
By September 1918, things are stable enough for an international congress of psychoanalysts in Budapest, where Freud calls for the establishment of psychoanalytic clinics for the poor.