. >> jerry steed, "wall street journal." thank you so much.ppreciate your time this friday. >> thanks, craig. >> twitter, not just a social networking site. it's apparently a high-tech mood ring. there's a new study of twitter being released by cornell university, says that people around the world are happiest in the morning. joins me now scott golder, a graduate researcher at cornell university's department of sociolo sociology. dot, first of all, tell me about the study and how you determined that people who are, in fact, happiest in the morning? >> hi. we -- thanks very much for having me. we examined a very large archive of tweets. we had half a billion messages that we collected over a period of a couple of weeks, and we did something very simple. we took a well-known set of keywords that are rated as positive words and negative words. >> keywords like what? >> i'll give you an example. an example of negative words include things like fear or fury or vulnerable. whereas positive words included things like delight, or happy. those sorts of