People are so suggestive that simply believing an alcoholic drink will make us feel better or socialise more easily at a party will greatly raise the chance of making it so, researchers said. This is because of the phenomenon of "response expectancies", or the way in which we predict how we will behave in different situations.
Because we expect that alcohol will make us more relaxed, for example, we automatically respond by becoming more open and chattier in a subconscious attempt to meet our expectation, psychologists explained.
Although most people would put the effect solely down to the alcohol, some studies suggest that our expectations of how the drink will make us feel also play a key role. Writing in the Current Directions in Psychological Science journal, researchers from Victoria University in New Zealand said: "the effects of suggestion are wider and often more surprising than many people might otherwise think."
Various other studies have shown that the power of suggestion can help people perform better in tests and even influence how well they respond to drug treatments, also known as the "placebo effect". Now certain experiments are showing that this also extends to our own behaviour, and that we change how we act and feel according to what we expect.
In one study cited by the authors, people who took a dummy drug which was allegedly supposed to make them feel more alert began to pay closer attention in a monitoring test because they expected the drug would make them do so. Asked how they felt after taking the drug, the patients said it made them feel more "alert" and "focused" and gave them "greater clarity of vision", reporting what they expected the effects of the drug would be.
The researchers wrote: "If I bring my rabbit's foot to the midterm, I will do well; if I drink this vodka tonic, I will be more sociable; If I take this pill, I will fell less depressed – these are just a few examples of response expectancies. "When we expect a particular outcome, we automatically set in motion a chain of cognitions and behaviours to produce that outcome – and misattribute its cause."