In addition to her "ten needs" theory, Karen Horney is also considered to be the founder of feminine psychology. Feminine psychology was a direct response to her disagreements with Sigmund Freud's theories of penis envy and the instinct orientation of psychoanalysis.

Phrenology was used to determine which psychological faculties a person possessed based on the bumps, divots, and shape of their skull. Phrenologists would place a person’s skull in their hand and feel for areas they believed to correspond with the brain’s functions. Phrenologists would also examine the skulls of the deceased and identify patterns in order to determine differences between male and female intelligence.

Noam Chomsky—a major figure in cognitive psychology and linguistics—challenged behavioral theories of language development, and instead argued for the idea that children possess an innate ability to acquire language. 

Kohlberg and Piaget are two theorists that studied moral development. Kohlberg described three stages of moral development: preconventional, conventional, and postconventional. On the other hand, Vygotsky is associated with cognitive development and the zone of proximal development. Erikson developed the psychosocial stages of development, which focus on specific crises that people encounter at each stage of life. Harlow studied contact comfort among rhesus monkeys. Bandura studied social learning theory and developed theories on observational learning and self-efficacy.

"John Locke" was the seventeenth philosopher that created the concept known as tabula rosa.  He believed that the mind was a blank slate and the experiences we have shape who we will become. 

Existential therapy is a humanistic therapy. It does not have a defined technique and it focuses more on existential questions (What do I want from life? How do I want to live my life? etc.) than changing any sort of cognitions or behaviors. Cognitive behavioral therapies encompass Aaron Beck's cognitive therapy, Meichenbaum's cognitive behavioral modification, and Albert Ellis' rational emotive behavior therapy.

Freud's theory included the Electra complex (the female version of the Oedipal Complex, where a child is sexually attracted to their opposite sex parent and is furious at their same sex parent), the Superego (one of the three parts of the personality which is the moralistic ideal of personality), and defense mechanisms (unconscious strategies people use to defend against harm, including repression, deflection, and denial). Pavlov is associated with behavioralism (specifically with conditioning in dogs). Yalom is associated with existential theory. Rogers is associated with person-centered therapy (humanistic therapy).  

REBT holds that problems arise when people believe they SHOULD or MUST be a certain way in order to get other people to accept them. Albert Ellis used crude humor to get his points across. He utilized these phrases as a way to describe these tendencies.

All of these therapists have conducted research on their theories. Freud specifically used case studies to do research. Rogers is known as the father of psychotherapy research for this groundbreaking new way of studying the therapy process. He recorded sessions and used this as material for research.