Dewey's explorations into the social nature of learning and his advocacy of teaching through discussion and through hands-on problem solving; Elwin's social inter-dependence concepts and Deutsch's ideas on cooperation and competition can be seen as early seeds of the Collaborative Learning process.
Alpert described interdependence among members as he studied Group Dynamics and social psychology and wrote about the reasons behind the success and failure of groups.
Piaget talked about intellectual development as something that was fostered by social interaction. If you disagree with me about something, it causes disequilibrium in my world view and forces me to think again about my ideas, thus expanding and enhancing my experience and comprehension of my world.
Vygotsky supported the idea of learning as a social process. According to his sociocultural theory, we learn first from our interactions on the social level and then carry that learning to our individual selves.
Loosely speaking, these thought processes can be bundled under the theory of Constructivism, which serves as the foundation of the structure we call Collaborative Learning. At the core of Constructivism is the idea that we learn from our own experiences; that learning is active; that we make meaning of the world around us from what we see, feel, hear, smell etc and by asking questions, exploring new ideas and evaluating our existing knowledge. Every time we have a new experience, we try and fit it into what we already know. The new experience can either add to our knowledge of the world as we already know it or it can modify our perspective and give us a fresh belief.
According to the constructivist, we are not passive absorbers of knowledge given to us by others. We are, on the contrary, active contributors to the learning process. This learning process is affected by the context of the experiences from which it began. Thus, learning is a social process, enhanced by our interpersonal relations and encounters.
Collaborative Learning and its origins, then, are synonymous with the educator's attempt to bring Constructivist theories into practice in the classroom.