Wasserman, E.A., Castro, L. & Fagot, J. (2015). Relational Thinking in Animals and Humans: From Percepts to Concepts” : In APA Handbook of Comparative Psychology, Volume 2, Perception, Learning and Cognition. Call et al. (Eds, pp 359-384). Washington DC, USA, American Psychological Association. 

Abstract – “The power of abstraction has its germ in sense-experience (1894, p. 264).” So wrote the famous comparative psychologist C. Lloyd Morgan well over a century ago. At issue was how  we progress from direct sense impressions to more abstract conceptual thoughts, a matter which still intrigues psychological scientists and about which we are concerned in the present chapter….