It's scary to think that choice might just be an illusion. Perhaps we are not so in control as we would like to be. In a conversation at the 92nd St Y, Malcolm Gladwell talks to Robert about the common sense of dissatisfaction felt by people required to justify a choice to others before they made it, and he brings up the unsettling idea of priming--that certain stimuli could predispose us toward certain choices or behaviors. Yale psychology professor John Bargh takes us a step further by describing an experiment where researcher Lawrence Williams was able to alter people's opinions without their knowledge using nothing but a simple cup of coffee.
UPDATE: The Williams & Bargh Yale coffee study "Experiencing Physical Warmth Promotes Interpersonal Warmth" was replicated in 2014 by researchers at three different universities, Kenyon College, Michigan State University, and University of Manchester. They did not observe the same results as in the original study. They conclude that the difference between the original and the replications may have been due to some issues with the methods of the original study ("The effect observed by Williams and Bargh may have been due, in part, to unconscious cues given by the researcher") or may simply have been due to chance. They are very careful in their language to not discredit the original study but they advise that future researchers be more cautious "when considering whether exposure to hot or cold temperatures impacts prosocial behavior." In sum: the original Yale study mostly still stands, but researchers now look the methods and results with slight skepticism (not outright disbelief though). You can check out the replications here: http://econtent.hogrefe.com/doi/full/10.1027/1864-9335/a000187