You've guessed it: Participants who had been reading about how they didn't have any free will chose to give more hot sauce to the poor fictional taster – twice as much, in fact, as those who read sentences supporting the idea of freedom of choice and responsibility.
In a recent study carried out at the University of Padova, Italy, researchers recorded the brain activity of participants who had been told to press a button whenever they wanted. This showed that people whose belief in free will had taken a battering thanks to reading Crick's views showed a weaker signal in areas of the brain involved in preparing to move. In another study by the same team, volunteers carried out a series of on-screen tasks designed to test their reaction times, self control and judgement. Those told free will didn't exist were slower, and more likely to go for easier and more automatic courses of action.
This is a young research area. We still need to check that individual results hold up, but taken all together these studies show that our belief in free will isn't just a philosophical abstraction. We are less likely to behave ethically and kindly if our belief in free will is diminished.
This puts an extra burden of responsibility on philosophers, scientists, pundits and journalists who use evidence from psychology or neuroscience experiments to argue that free will is an illusion. We need to be careful about what stories we tell, given what we know about the likely consequences.
Fortunately, the evidence shows that most people have a sense of their individual freedom and responsibility that is resistant to being overturned by neuroscience. Those sentences from Crick's book claim that most scientists believe free will to be an illusion. My guess is that most scientists would want to define what exactly is meant by free will, and to examine the various versions of free will on offer, before they agree whether it is an illusion or not.
If the last few thousands of years have taught us anything, the debate about free will may rumble on and on. But whether the outcome is inevitable or not, these results show that how we think about the way we think could have a profound effect on us, and on others.