KentuckyFC writes "People can be accurately classified according to their email habits, say scientists from Yahoo Research in NYC, who have been studying the way 125,000 people use email on university campuses in the US and Europe. The team found that people fall into two clearly distinct types of emailer. The first group, 'day labororers,' tend to send emails throughout the normal working day between 0900 and 1800 but not at other times. On the other hand, 'emailaholics' tend to send emails throughout the waking hours from 0900 to 0100. These groups are pretty stable: roughly 75% of users stay in the same group over a two-year period. That gives a pretty good way of classifying individuals that could be used by demographers. Interestingly, the technique can also be used to spot spambots which do not fit into either group."