Edward John Mostyn "John" Bowlby (26 February 1907 – 2 September 1990) was a British psychologist, psychiatrist and psychoanalyst, notable for his interest in child development and for his pioneering work in attachment theory. Bowlby was “more a theoretician than a therapist” and he devoted his attention more to “observable behavior than to the inner world.” Nevertheless, attachment theory should be seen as “a child of psychoanalysis” (Holmes 2002, 153).
Psychologist Lawrence Kohlberg presented that moral development is a continual process. Kohlberg expanded on Jean Piaget's work to explain how children developed moral reasoning. Kohlberg's theory outlined six stages within three different levels.
A famous psychologist Adler's theory suggested that every person has a sense of inferiority. From childhood, people work toward overcoming this inferiority and asserting their superiority over others. Adler referred to this as 'striving for superiority' and believed that this drive was the motivating force behind human behaviors, emotions and thoughts.