http://www.cs.unt.edu/~rada/papers/mihalcea.aaaiss06.pdf

"What are the sources of happiness and sadness in everyday
life? In this paper, we employ ‘linguistic ethnography’ to
seek out where happiness lies in our everyday lives by
considering a corpus of blogposts from the LiveJournal
community annotated with happy and sad moods. By
analyzing this corpus, we derive lists of happy and sad
words and phrases annotated by their ‘happiness factor.’
Various semantic analyses performed with this wordlist
reveal the happiness trajectory of a 24-day (3am and 9-10p
are most happy), and a 7-day week (Wednesdays are
saddest), and compare the socialness and humancenteredness
of happy descriptions versus sad descriptions.
We evaluate our corpus-based approach in a classification
task and contrast our wordlist with emotionally-annotated
wordlists produced by experimental focus groups. Having
located happiness temporally and semantically within this
corpus of everyday life, the paper concludes by offering a
corpus-inspired livable recipe for happiness1. "