Price may exert a non-conscious influence on expectations of product quality. These expectations affect the actual product performance. These expectations can be induced through advertising. Baba Shiv, University of Iowa ( Stanford ) and his colleagues Dan Ariely, Ziv Carmon did a fascinating study to examine this phenomenon. The findings were summarised by Akshay R. Rao, University of Minnesota. In the study, two groups were given a mental acuity enhancing drink—one costing $ 1.89 and the other $ 1.0. They were asked to solve the puzzles after consumption of the drink. The group which had consumed full-priced drink solved more puzzles than the group that received discounted price drink. The discounted price receiving group had less expectations about the efficacy of the drink as far as their problems solving ability is concerned. These lessened expectations sub-consciously and affected the actual product performance. It is a demonstration of price-quality effect. In many instances, psychology is more important than engineering in product design.