Does Alcohol Really Work Like Truth Serum?

As the saying goes, “in vino veritas”. But are you actually more likely to speak your mind when you’re drunk?

Laura Simmons - Editor and Staff Writer

Laura Simmons

Laura Simmons - Editor and Staff Writer

Laura Simmons

Editor and Staff Writer

Laura is an editor and staff writer at IFLScience. She obtained her Master's in Experimental Neuroscience from Imperial College London.

Editor and Staff Writer

two women drinking wine and talking

Does drinking alcohol make you more likely to tell the truth? Image credit: Photoroyalty/

It’s an adage that many of us would swear by: that being drunk loosens our tongues such that we air our deepest-held thoughts and grievances, where usually our inhibitions would prevent us from doing so. But is it really the case that, as the saying suggests, in wine there is truth?

Alcohol and the brain

There’s still a lot that neuroscientists don’t understand about how alcohol affects the brain – despite the fact that an estimated 85.6 percent of US adults have consumed an alcoholic drink at some point in their lives. 


You can check out a recent episode of our podcast The Big Questions for our conversation with neuropsychopharmacologist Professor David Nutt, which did shed some light on what scientists know on this topic (and, importantly, how we may soon have an alternative beverage that offers all of the fun with far fewer drawbacks!)

It’s fair to say that much of the research to date has, understandably, focused on the widespread neurological damage that chronic alcohol use can cause. Thankfully, most people’s alcohol consumption does not tip over into problematic territory – but that does not mean that the brain is unaffected.

A recent study published in PNAS demonstrated that even a single dose of alcohol led to lasting changes in the neurons of mice and flies. Another study claimed that consuming only two units of alcohol per day could be enough to shrink the brain. And then there are the psychological effects: there’s even some evidence that “beer goggles” may have more truth to them than you might think! 

Given alcohol’s potency, then, is it so unbelievable that getting plastered could pave the way for some uncomfortable truth-telling?

Losing your inhibitions

One of the major brain areas affected by alcohol is unfortunately also the area that is responsible for reasoning, judgment, and generally making good life choices. We’re talking about the prefrontal cortex. Alcohol’s effect on this area also leads to the characteristic loss of inhibition that one experiences when one has had a few too many.

This can manifest in an increased tendency towards risk-taking. From risky sexual behavior, to gambling, to probably the most obvious one of all – drunk driving – being under the influence makes it easier to ignore the little voice in your head telling you that this isn’t such a good idea. Most relevant to the topic at hand, losing your inhibitions may lead to you saying things you’ll wish you hadn’t.

It’s not all about the negatives though. After all, feeling more confident is an important reason why people choose to drink in the first place. It is possible to enjoy this sensation while also keeping safe – just make sure you’ve decided on the designated driver ahead of time, and maybe also ask them to steer you away from your boss at the Christmas party before you start telling them what you really thought about that meeting…

Does alcohol change your personality?

So alcohol can clearly affect our behavior in profound ways – but can we go so far as to say that it changes our personality?


A 2017 study looked more deeply at the concept of a “drunk personality” and applied the widely used five-factor model (FFM). The FFM encompasses five broad personality traits: neuroticism, extraversion, agreeableness, openness to experience/intellect, and conscientiousness. The researchers recruited 156 participants aged 21-30 and asked them to rate their own usual personality traits after a drink. One group of participants was then given vodka lemonades until their blood alcohol concentration reached 0.09, and after around 35 minutes they were asked to take part in a series of activities.

Video recordings of the activities were used to allow independent observers to assess the drunk and sober individuals’ personality traits. These observations were compared with the individuals’ own ratings from the start of the experiment. Perhaps unsurprisingly, there was one personality trait that particularly stood out – extraversion. Not only did the participants themselves report that they felt more extraverted after a couple of cold ones, but this was actually borne out when they were observed by other people. 

Many of us can relate to the feeling of becoming livelier when we’re a bit tipsy, even to the point where we behave in a way that’s totally at odds with our usual disposition. The authors of the 2017 study felt that their results were a good basis for further research into the “drunk personality”, stating, “We see the present findings as demonstrating the viability of viewing drunken comportment through the lens of personality theory, a perspective that opens up new research opportunities with important implications for clinical assessment and related treatment interventions.” 

However, the team did stress that, in general, people rate their drunken personality changes as more significant than can actually be observed by other people. Alcohol may make you come out of your shell a bit, sure – hence the deep-and-meaningfuls you may find yourself having with strangers in the smoking area – but to say that it alters your personality is going a step too far.

Is there truth in wine?

It stands to reason that someone behaving in a more extroverted way, with the added spice of alcohol-induced inhibition loss, might say a few things they regret in the morning. However, a drunk person running their mouth isn’t necessarily a reflection of their true feelings.

Addiction treatment provider the Gateway Foundation suggests that context is key. “Intoxicated individuals are more likely to respond emotionally in social situations due to inhibited emotional processing,” they say on their blog

Unfiltered expressions of emotion, particularly coming from people who are more reserved when sober, may be more likely to be true. But lashing out in anger? It could be that the person is uninhibited enough to simply say the worst thing that comes to mind, rather than what they truly feel.

There are almost as many proverbs about truth-telling and alcohol as the British have words that mean “drunk” (anyone fancy getting gazeboed tonight?). It’s clearly something that has stuck in the collective consciousness. However, as we’ve seen, while there is robust evidence that booze loosens the tongue, there really is nothing to suggest that what you come out with is anything close to the truth.


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