Dr Tom Stafford, a lecturer at the University of Sheffield and co-author of the book Mind Hacks, believes that the same fundamental learning mechanisms that drive gambling addicts are also at work in email users. “Both slot machines and email follow something called a ‘variable interval reinforcement schedule’… This means that rather than reward an action every time it is performed, you reward it sometimes, but not in a predictable way. So with email, usually when I check it there is nothing interesting, but every so often there’s something wonderful – an invite out, or maybe some juicy gossip – and I get a reward.” This is enough to make it difficult for us to resist checking email, even when we’ve only just looked…
http://www.guardian.co.uk/technology/2008/aug/28/email.addiction