The HItchhiker's Guide to Neutrality

A survey of English-language books of the 20th century points to a decline in the number of words describing emotion. Specifically, the study focused on words describing anger, disgust, fear, joy, sadness, and surprise. One of the many interesting findings was that fear-related words made a comeback in the '70s and continued to grow in number from then on: http://www.psmag.com/blogs/news-blog/less-emotion-british-english-american-books-literature-54182/