Aaron beck is a psychiatrist and professor at the university of Pennsylvania. He is known as the father of cognitive therapy, and is most famous for his pioneering theories, cognitive triad theory. Beck's cognitive triad is is a triad of types of negative thought present in depression and forms part of his his Cognitive Theory Of Depression. The triad goes as so:  1.The self (i.e., self is worthless) 2.The world/environment (i.e., world is unfair), and 3.The future (i.e., future is hopeless.) the cognitive theory of depression states that depression acts as a result of maladaptive, faulty, or irrational cognitions taking the form of distorted thoughts and judgments. This dissertations can be learn socially, observational, from family or friends or from a lack in experiences having to deal with the development of adaptive coping skills. The theory suggests that with who suffer from depression have different thoughts then those who don’t, which is the main cause of their depression. Beck theory believes that negative thoughts, generated by dysfunctional beliefs are the main cause of depressive symptoms, which in turn causes you to become more depressed. Beck says that there are three dysfunctional belief themes or schemas, which dominate depressed people's thinking: 1) I am defective or inadequate, 2) All of my experiences result in defeats or failures, and 3) The future is hopeless. Together these three dysfunctional beliefs make up Negative Cognitive Triad.