I believe the incorporation of psychology in design theory is incredibly important. In order to plan and predict how users will respond to a product, we must understand why they will respond in that way and what processes are utilised in order for them to come to that conclusion. Butler, Holden and Lidwell (2003, p. 148) maintain that cognitive load theory plays a major role in the design of a product. According to Budd (cited in Taylor, 2013) “To be a good designer in today’s society, you need to have an understanding of psychology, human behaviour, and the little shortcuts, the little quirks, in the way people operate.” Once you have this information on how the human brain and thinking works, you can tailor your product or design to get the desired emotion from the user.
Butler, J., Holden, K., & Lidwell, W. (2003). Performance Load. In Universal Principles of Design (pp. 148-149). Massachusetts: Rockport.
Taylor, A. R. (2013). The Psychology of Design Explained. 2015, from http://www.digitalartsonline.co.uk/features/graphic-design/psychology-of-design- explained/