Most and Least "Happy" Words in English

"Hedonometer.org is based on the research of Peter Dodds and Chris Danforth and their team in the Computational Story Lab, including visualization by Andy Reagan, at the University of Vermont Complex Systems Center, and the technology of Brian Tivnan, Matt McMahon and their team from The MITRE Corporation."

"To quantify the happiness of the atoms of language, we merged the 5,000 most frequent words from a collection of four corpora: Google Books, New York Times articles, Music Lyrics, and Twitter messages, resulting in a composite set of roughly 10,000 unique words. Using Amazon’s Mechanical Turk service, we had each of these words scored on a nine point scale of happiness: (1) sad to (9) happy."

source: http://hedonometer.org/words.html