Does This Test Prove You're An Introvert?

lemon, fruit
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If there's one thing people almost universally love, it's taking tests that supposedly reveal inner truths about themselves. I'm not exempt from this habit; I love experimenting with measures that claim to shine light on who we are as people, and thinking about how this new knowledge can lead us to be more aware members of society. Largely being of an introverted persuasion myself, then, I was thrilled to discover a test that claims it can prove I'm an introvert. Does the lemon juice personality test actually work, though? Now seems like a great time to find out, so I gave it a shot.

The history of this at-home introversion test, which Melissa Dahl recently wrote about over at Science of Us, goes back to the 1960s. Psychologists and married couple Hans and Sybil Eysenck developed the lemon juice test as way of measuring whether people are introverts or extroverts. This duo was pretty important when it came to personality research and basically set the stage for later experiments on the subject, which leads me to wonder: Why have we always been so interested in ourselves?

The study of personality is a pretty interesting topic to a lot of people: Many of us are continually searching for our identities and for ways to express ourselves. Determining whether or not we're introverts, for example, may help us improve our communication styles, our personal needs, and the way our close friends and loved ones come to understand us. There's also a lot of interesting research out there on whether or not we can change our personalities (and if possible, should we?), as well as how our personalities impact our success and our careers.

Here's what happened why I tested the lemon juice personality test on myself.

What You Need To Conduct The Test:

To conduct this experiment, all you need is a piece of string, a lemon (or simply lemon juice from a bottle, like I used), a cotton swab, and yourself. Simple, right?

How It Works:

In the original experiment — the one that was conducted back in the 1960s — the Eysencks used sensitive weighing equipment to measure how much saliva was absorbed into a cotton bud before and after people were exposed to the juice. However, for the purpose of this article, I'm doing a simplified version that stems from Brian Little's book Me, Myself, and Us, which involves simply dangling the cotton swab from a piece of string.

First, place one end of the cotton swab on your tongue for 20 seconds. (Yes, it's going to feel a little weird.) Then, put five drops of concentrated lemon juice on your tongue (I used the kind you can buy at the supermarket, nothing fancy), swish it around, then swallow. Then, place the other, clean end of the cotton swab on your tongue and hold it for about 20 seconds. Remove the cotton swab from your mouth and let it dangle from the string. If the side you used after the lemon juice is heavier (hangs lower on the string), that means you produced more saliva post-lemon juice. And this means (dun dun dun) you're likely an introvert. More on why in a moment.

Now, the concept is the same whether you use a measuring scale or the string, but in the effort of full disclosure, I only tried it with the string, so I can't promise my results would be the same in both methods. The main takeaway, though, is that if your tongue produces more saliva post-lemon juice, this means you're likely an introvert. How come? Let's take a look at...

The Science Behind It All:

The Reticular Activating System (RAS) is the system in control of your responses to various forms of stimuli, including both taste and social contact. RAS controls, for example, the amount of saliva you produce in response to food — in this case, lemon juice. Scientists now believe that if introverts already have a high level of activity in their RAS because they're generally highly stimulated as their baseline, then a small amount of stimuli — like lemon juice on the tongue — is all that's needed to produce a big reaction. Hence, the idea that introverts are likely to produce a large amount of saliva in response to a little bit of lemon juice. On the flip side, an extrovert isn't likely to have such a large reaction, and will produce a smaller amount of saliva in response to the lemon juice.

My Results:

The verdict is in, and... I'm an introvert! After I swished lemon juice around in my mouth, I applied the clean end of the cotton swab to my tongue, I used the string to "weigh" it, and found that instead of hanging horizontally, the post-lemon side hung lower.

Personality tests and quizzes pretty much always tell me that I'm an introvert, so I'm not super surprised. I also fit many of the usual criteria for being an introvert in my daily life: I prefer small crowds, dislike loud background noise, and require lots of alone time to gather my thoughts and recuperate after big social activities. And yes, I definitely produced loads of saliva after swishing around that lemon juice — ew.


In all honesty, I think this experiment is pretty cool. Admittedly, not everyone is a "perfect" introvert or extrovert (and when we bring in the whole ambivert discussion, that really complicates things) but I think it's fascinating when we combine psychology and science to learn more about ourselves. I think the link between our mental status and our physical bodies is particularly interesting, as well: Who knew something as basic as my saliva could reveal something about my response to stimuli and the outside world?

Images: eftoefto/Moment/Getty Images; Giphy (3); Marissa Higgins/Bustle (2)