It’s Evo-Lit-ionary: Why Humans Like Drinking Alcohol

By: Luke Harbison, Maddie McCall, Nicole Moughrabi, and Adora Nguyen

It’s no secret that many (if not most) people like to drink — fruity wine coolers, a cold beer, some mixed concoctions that are most definitely shaken, not stirred. But, why? Especially considering that alcohol itself is bitter, toxic, and leads to us being vulnerable and making poor decisions, there must be some scientific reasons other than having fun while losing inhibitions.

And there are — alcohol has been utilized as a medicinal tool, a way to find pleasure and feel good, and as it turns out, our widespread preference for alcohol may even be a byproduct of an evolved adaptation.

But before we get too much into evolution, let’s take a quick look into how alcohol has been used in more recent times.

Medicinal Alcohol


One interesting historical use of alcohol was medicinal. For instance, in Ancient Egypt wines and beers were often used as forms of medicines that could help with a wide-range of ailments: a beer mixed with coriander, bryony, flax, and dates could ease stomach problems; coriander mixed with fruit and beer could help with blood in someone’s stool; salves for herpes were created from coriander, seeds, myrrh, and fermented honey. Alcoholic ingredients were also used as laxatives, emollients (which are soothing lotions for your skin),  and even  aphrodisiacs. In short, alcohol was a key ingredient in healing during ancient times.

But, most of us aren’t living in ancient Egypt, and we can just run to the closest pharmacy to pick up our (much more effective) meds instead of making them ourselves. Why do we still continue to drink alcohol?


One explanation is that we’ve evolved to like the feeling of being drunk (or at least tipsy, for those who might only indulge in a glass of wine once a week). One clue that this might be the case is that alcohol stimulates reward circuits in our brains. When we consume alcoholic drinks there are many chemical reactions happening, namely the release of dopamine, which helps us to feel good. This release of dopamine happens in the nucleus accumbens, which is just a fancy name for the reward center of our brains. In short, alcohol can help us feel good. It helps us relax, offers us a way to connect with others in social settings, and can enhance the food we’re eating. But why does it make us feel good?

Some researchers have argued that the hedonic (or pleasurable) qualities of a stimulus (like food, or water when you’re really thirsty, or sex) are indicators of its “fitness goodness,” or in other words, whether something will help us survive or pass on our genes. Animals who found pleasure in “fitness good” stimuli were therefore more fit than those who didn’t (evolutionary speaking, meaning better able to survive, reproduce, and pass on their genes — not necessarily able to lift weights). This means that animals that sought out those pleasure-rewarding stimuli were overall more successful than those who didn’t. So, the fact that alcohol feels good to us suggests that alcohol–or something associated with alcohol–might have actually been good for our ancestors’ fitness.

Before we get to what that “something good” might be, though, it’s important to point out that this reward mechanism can go awry, which in the case of alcohol and other dopamine-stimulating drugs, it certainly can. There are some studies that state alcoholism can be considered an “evolutionary hangover” of this reward mechanism. Over time, humans have become very skilled at seeking out pleasurable stimuli over more important or necessary things, such as food or water, which is a not-so-good thing.

The Genetics of Alcoholism 

There are multiple studies that put forth the argument that certain genes were evolved to help with the breakdown of ethanol and metabolize alcohol–another clue that alcohol is a part of our evolutionary past in some way.


However, consuming too much of ethanol can have great risk, considering that these specific genes can also influence a person’s risk of becoming an alcoholic. Various alleles (or versions) of these genes may determine the likelihood of someone developing alcoholism based on how they break down ethanol. In short, two people could drink the same amount over a span of a few weeks, but the person whose genes are more inclined to addictive behaviors and efficient breaking down of alcohol runs the higher risk of becoming addicted. It is likely, based on these and other studies, that these genetic risks are at least in part explained by how rewarding people with different gene variants find the consumption of alcohol.

Risk Taking Behavior

Furthermore, other studies have shown that an important behavioral predictor of alcoholism is tied to one’s levels of impulsivity; the more impulsive someone is, the greater chance of excessive consumption of alcohol and, ultimately, alcoholism. Impulsive behaviors may arise from genetic properties or can be influenced by social factors. Thus, alcoholism is not thought to be caused by one element, but rather a combination of various genetic, behavioral, and learned traits (it’s nature AND nurture — no “vs” here).


We humans also have a tendency to start drinking at a young age, possibly even younger than certain laws may allow for. This may be due to alcohol being a (literal) forbidden fruit; some studies have shown that adolescence is the time in which behavior prohibited by authority seems enticing (i.e. underage drinking). Adolescents see themselves as being invincible and unafraid of the unknown, which prompts them to actually seek out certain ambiguities — such as underage drinking.

As you can easily guess, underage drinking is not really a good thing to do; not only is it illegal in some societies, but it can also hinder brain development, considering the brain isn’t fully developed until you’re almost 30. So while drinking alcohol can make us feel good, there are very real dangers that come with drinking.                                                                                                                                                                     

Which brings us, finally, to what evolutionary psychologists consider the underlying cause as to why humans like drinking alcohol: for our ancestors, it all came down to food.

Ripe Fruit and Digestive Fermenting

A major challenge our ancestors faced was obtaining enough food, and food that wouldn’t be dangerous to us. A solution to this problem was to evolve taste preferences that helped us determine which foods offered the most calories and aversions for things that were toxic. For example, humans tend to enjoy rich umami tastes, which are associated with foods rich in fats and proteins, such as meats. In contrast, we tend to avoid very bitter tastes, as bitter foods tend to contain compounds that are toxic to us.

We also like sweet tastes, which are associated with high-sugar foods, such as sodas and cakes in modern times. This sweetness preference is why our ancestors feasted on delicious, ripe fruit (the closest thing to cake that they had available)… which also just happened to have high levels of ethanol. This also answers the question as to why we enjoy a drink that can be so bitter. Because it wasn’t always so bitter — it used to be sweet and fruity.

This main hypotheses that explains why we enjoy alcohol is called the Drunken Monkey Hypothesis. By studying monkeys, who are our closest evolutionary relative, we find that their diet is predominately plant-based; this supports multiple pieces of evidence that our ancestors also ate many plants. But while monkeys often times seek out ridiculously ripened fruit because of their high level of calories, those fruit also have high levels of ethanol (reaching 1%), which then ferments while digesting, and ends with the monkeys becoming drunk. This can also happen to any animal that eats the fruit, and below is a video of a bunch of animals who hopefully have their own DD.



But notice that the animals go after the fruit because they are ripe and have high levels of calories — becoming drunk only happens coincidentally. This is called a by-product, or a secondary characteristic that gets carried along by an adaptation, which is the actual evolved solution to a survival or fitness problem. So in this case, our ancestors faced the problem of selecting the very best fruits to eat, evolved a preference for sweetness that solved this problem, and coincidentally, also developed a taste for the ethanol that was also in the ripe fruit.

Take Aways

There are many reasons as to why modern-day humans enjoy drinking alcohol, and if you ask anyone you’re almost guaranteed a few of those answers. However, alcohol has been used for more than just drinking. Just to recap:

Alcohol was once used in ancient medicines that would solve an assortment of ailments (although, today the main ailment solved by alcohol is social anxiety or a stressful job).

But as far as researchers can tell, the deeper evolutionary reason as to why we drink is because our ancestors feasted on ripe fruit whenever they could get it, and their taste for fruit carried on to us. Our drunk cousins, the monkeys, can demonstrate this with their penchant for alcoholic fruity drinks.

Which can unfortunately lead to large amounts of consumption, potentially resulting in alcoholism. Different genes and chemicals are used to breakdown alcohol, but these genes and chemicals can also determine whether or not someone is more likely to become an alcoholic.

When it comes to drinking alcohol, no matter the reason why or how, it is important to be safe and be smart. Remember, it’s survival of the fittest — not the survival of the drunkest!