Mood Detection/Unsound Science

Thinking about the various ways of collecting data from people, I've been looking into mood detection as a possibility. However there doesn't seem to be much sound science behind it. There is an argument that body temperature is linked to a person's emotional state but this varies from person to person and does not always communicate the same information—the same body temp. can mean different moods.

There is a mood detector App available: http://www.schvarts.com/detectors/mood-detector/ but it's more of a toy (and looks terrible).

Also came across this: courses.engr.illinois.edu/ece445/projects/fall2005/project2_presentation.ppt which is a student's proposal for a system which reads the mood of the user and creates music playlists based around these readings—which is similar to what I was thinking but it's a clunky and invasive system, involving sensors being placed on the user.

A system that could be linked to your itunes and remember what music you listen to when you’re in a certain mood might have better functionality—again though, the science is questionable.