In the present dissertation, I propose a general, robust, and objective characteristic of the information environment, according to which negative information is more diverse than positive information. I present an explanatory framework for this phenomenon based on the non-extremity of positive qualities. Specifically, most attribute dimensions host one “positive” range which is surrounded by two distinct “negative” ranges, resulting in a greater diversity of negative compared to positive attributes, stimuli, and information in general. Chapter 1 of my dissertation reviews evidence (...) for the proposed greater diversity of negative information, showing that positive stimuli are consistently perceived as more similar than negative stimuli. Chapter 2 presents a line of research that demonstrates the same phenomenon in the domain of person perception. People perceive other people they like as more similar to one another than other people they dislike. I further suggest that the greater diversity of negative information as an “extrapsychic” phenomenon can account for a number of valence asymmetries in information processing that have previously been explained based on “intrapsychic” affective reactions. In line with this idea, Chapter 3 presents research showing that negative words enjoy a recognition advantage over positive words because they are more diverse. Chapter 4 discusses limitations, open questions and further implications of the current empirical findings and of the explanatory framework provided. (shrink)