Eighty per cent of adults in the US and the UK are moderate users of the psychoactive drug, caffeine.
Of all the effects it has on our minds—enhanced attention, vigilance and cognition—perhaps least known is its tendency to make us more susceptible to persuasion.
This was demonstrated in a study by Pearl Martin and colleagues at the University of Queensland in Australia (Martin et al., 2005). In their experiment they tried to convince participants to change their minds about the controversial issue of voluntary euthanasia.
Participants were told that some in the university agreed that people should be allowed to end their own lives under certain circumstances, while others did not. In fact participants were chosen because they agreed that voluntary euthanasia should be legal and the experimenters wanted to see if they could be persuaded otherwise.