The University of British Columbia conducted a study recently, suggesting people are more likely to lie in text messages than they are in all other forms of communication.

This was done with a pretty ingenious role-playing game of 'stock market.'  170 students were analysed via face-to-face, audio, video and text message communications as they play the rolls of brokers selling stock or consumers out to buy the aforementioned stock.  Just before the brokers were to make their sales pitch to consumers, they were informed that the stock had lost half its value, which set the stage for the buyers to report back to researchers, determining how often they'd been lied to.