John Bowlby completed his medical school training at Cambridge University in England. Prior to beginning his practice, he worked as a volunteer at a residential treatment center for children. He began considering the influence of family lives, particularly the actual experiences of children (as opposed to internal fantasy) on the children he worked with. He pursued psychoanalysis with a training analysis. Eventually, this led to conflicts with his training analyst, Melanie Klein, and movement away from other psychoanalysts. He developed interests in ethology (Goldberg, 2000) and cybernetics (Bretherton & Munholland, 1999). Using these interests in psychoanalysis, child development, ethology, and cybernetics; he wrote several books explicating attachment theory.