The old Latin saying “In vino veritas”, which means “In the wine lies the truth”, is just one of the many expressions that perpetuate the idea that alcohol is a kind of truth serum. This phrase is attributed to Pliny the Elder, a Roman scientist, historian and soldier, although similar expressions can be traced back to ancient Greece. But are drunk people more honest?
Are they more honest? The answer is both yes and no, experts said.
Alcohol “makes us more likely to say whatever is on our mind. In some cases, this could be the truth. In others, it could be what you think is the truth in your state of intoxication,” said Aaron White, chief of the Epidemiology and Biometrics Branch at the US National Institute on Alcohol Abuse and Alcoholism.
So there is definitely a higher likelihood of someone speaking their mind after a few drinks. But there’s also the possibility that he might say something that sounds real while drunk, but that he wouldn’t take seriously when sober. For example, a drunken friend might make bold promises to move to another city or quit his job, only to retract them the next morning.
What does science say about drunk people and honesty?
Although an extensive search did not yield direct results for research on how alcohol influences honesty, studies of alcohol’s impact on personality, emotions, and cognition support this idea.
For example, a 2017 study published in the journal explored how participants’ personalities changed after they drank enough vodka with lemon to reach a blood alcohol concentration of 0.09 percent, just above the legal limit of driven in USA and England.
Outside observers noted that the biggest change in the participants’ personalities after drinking alcohol was that they became much more outgoing. Although the study did not investigate whether , it stands to reason that someone who feels more relaxed in a social setting is also more likely to be honest.
Alcohol’s ability to help people become more sociable may help them express their thoughts, but White says its effects on emotions can make those thoughts more volatile.
“In general, we find that alcohol consumption tends to intensify emotions. We might find ourselves smiling more and talking louder in pleasant interactions, but perhaps, as researcher (emeritus professor at Stanford University in the US) Claude Steele said, we might also be more prone to ‘crying in beer’ in less pleasant situations”, said Michael Sayette, professor of psychology at the University of Pittsburgh (USA).
How is the brain affected by alcohol?
These heightened emotions might cause people to speak their minds sober, but they can also put them in a volatile state where they say something they don’t really believe or deeply regret later. It’s similar to how alcohol makes some people more likely to become violent or gamble, actions that might cross their minds when they’re sober, but which they would have enough self-control to avoid.
“Because alcohol can change our thoughts and feelings, it’s not surprising that our behaviors can also become more extreme,” Sayette said. These effects come from alcohol’s ability to cause disinhibition, meaning that a person is more likely to act on their impulses. This happens because alcohol dampens signals in the prefrontal cortex, a region of the brain that regulates behavior and controls impulses, White explained.
What’s more, alcohol also suppresses the amygdala, a structure deep in the brain known to trigger feelings of fear and anxiety. While a person is awake, the amygdala generally sends warning signals that can stop a person from saying or doing things that could lead to a social blunder, but those signals quiet down after a few drinks.
So are people drunk? Sure, people might be more likely to reveal secrets after a few glasses of wine, but they’re also more likely to say something they don’t really believe and regret it the next morning. The effects of alcohol on the mind are simply too complex to have a clear effect on honesty.
“Alcohol is not a truth serum. That’s for sure,” White said.
