The phrase “In vino veritas”—Latin for “In wine, there is truth”—has been passed down for centuries, suggesting that alcohol has the power to unearth hidden truths.
But does drinking really make people more honest, or is this just another myth?
A Complex Relationship
It’s tempting to believe that alcohol functions as a truth serum, loosening inhibitions and compelling people to reveal their deepest thoughts.
There is some truth to this idea—alcohol does make people more likely to speak their minds. But as experts point out, that doesn’t necessarily mean they are being truthful.
“Alcohol makes us more likely to say whatever’s on our minds,” says Aaron White, leader of the National Institute on Alcohol Abuse and Alcoholism’s Epidemiology and Biometry Branch.
“In some cases, that could be the truth. In some cases, it could be what you think is the truth in your intoxicated state.”
That last part is crucial: what you think is the truth in your intoxicated state.
This means that while someone might speak more freely after a few drinks, their statements may not always be accurate.
Alcohol’s Effect on Personality and Inhibition
A 2017 study published in Clinical Psychological Science explored how alcohol affects personality.
Participants were given enough vodka lemonades to reach a blood alcohol concentration (BAC) of 0.09%—just over the U.S. and U.K. legal driving limits.
Observers noted that the most significant change in their behavior was increased extroversion.
This shift in personality suggests that alcohol doesn’t necessarily make people more honest, but rather, it makes them more expressive.
If someone feels more socially at ease, they may be more willing to share thoughts they would normally keep to themselves.
However, that doesn’t mean their statements are entirely truthful—just that they’re unfiltered.
The Myth of “Liquid Courage”
We often hear that alcohol gives people courage to say things they wouldn’t otherwise. But courage doesn’t always equal honesty.
What alcohol actually does is weaken inhibitions by dampening activity in the prefrontal cortex, the part of the brain responsible for impulse control and decision-making.
Additionally, alcohol suppresses the amygdala, a brain structure that triggers feelings of fear and anxiety.
When this happens, a person may feel emboldened to say things they normally wouldn’t, but this isn’t necessarily because they’re telling the truth—it’s because they’re less concerned about the consequences of their words.
Emotionally Charged Speech and Regret
Another reason why alcohol-induced honesty is unreliable is that drinking amplifies emotions.
“We generally find that drinking alcohol tends to intensify our emotions,” says Michael Sayette, a psychology professor at the University of Pittsburgh.
“We may find ourselves smiling more and speaking more loudly in pleasant interactions, but… we might also be more likely to cry in our beer in less-pleasant situations.”
This emotional intensity can lead to exaggerated statements.
For example, a person might drunkenly declare that they hate their job or are moving to another country, but when sober, they may not actually feel that way.
More Than Just Words
The same disinhibition that leads people to say bold things also makes them act in extreme ways.
Studies show that alcohol increases the likelihood of violent behavior, impulsive gambling, and risky decision-making.
These behaviors stem from the same cognitive impairment that affects speech—when sober, a person may think about doing something, but their brain tells them not to act on it.
Under the influence, that mental filter is weakened.
If alcohol made people inherently truthful, we’d expect it to make them act on their true feelings all the time.
But instead, we see erratic, unpredictable behavior. This inconsistency suggests that alcohol doesn’t necessarily reveal the truth—it just amplifies whatever is on a person’s mind at the time, whether true or not.
Alcohol is Not a Truth Serum
While alcohol may make people more talkative, it doesn’t guarantee honesty.
It weakens inhibitions and increases emotional expression, but that can lead to both genuine confessions and exaggerated statements.
“Alcohol is not a truth serum,” says White. “That’s for certain.”
So, the next time someone tells you that a drunk person always speaks the truth, take it with a grain of salt. What they say might be honest—or it might just be the alcohol talking.
