Attractive Things Work Better  

Until recently, emotion was an ill-explored part of human psychology. Some people thought it an evolutionary left-over from our animal origins. Most thought of emotions as a problem to be overcome by rational, logical thinking. And most of the research focused upon negative emotions such as fear, anxiety, and anger. Modern work has completely reversed this view.

Norman, Donald A. JND.org (2003). Design>User Interface>User Experience>Emotions

Exploring Types and Characteristics of Product Forms  

Incorporating emotional value into products has become an essential strategy for increasing a product's competitive edge in the consumer market. It is therefore important for product manufacturers to understand how products affect consumers' emotions. This study was undertaken to investigate the types and characteristics of household products that elicit pleasurable responses, in particular among young, college-age consumers. The results of the study could suggest the types and characteristics to consider when developing pleasurable products aimed at young consumers.

Chang, Wen-chih and Tyan-Yu Wu. International Journal of Design (2007). Design>User Interface>User Experience>Emotions