The self develops out of a conversation, by using symbols.
Mead was responsible for developing the concept of symbolic interaction, the most important factor in human social relationships. Symbolic interaction consists of interpretation, that is, comprehension of the meaning of other person's actions. The foundation of cooperation is social relations and it relies on the communication process in which meanings are conveyed. Non-symbolic interactions are those in which partners respond to each other's actions directly.
Mead emphasized that the interactions and even cooperation, as seen in animals is purely biological. As against this, humans can interpret and mutually define their actions, rather than just reacting to them.
In Mead's opinion, human thought, experience and conduct are essentially social. Human beings interact with each other in terms of symbols; the most important of which are contained in language. Without symbols, humans will not interact and therefore no human society. Mead was of the opinion that animals respond through gestures, but their interactions are unconscious and non-rational.
Only human beings are capable of abstract thinking. The human mind can have inner conversation and adopt an attitude towards oneself. Human cognition has a symbolic nature. Animals, according to Mead, do not possess this ability, for they do not possess self.