Cognitive Daily

Blogging on Peer-Reviewed ResearchDo people ever tell you to “just smile, you’ll feel better”? If you’re like our daughter Nora, you hear it a lot, and you get annoyed every time you hear it. Telling a teenager to smile is probably one of the best ways to ensure she won’t smile for the next several hours. But the notion that “smiling will make you feel better” has actually been confirmed by research. There are several studies demonstrating that people are happier when they smile, at least in certain circumstances.

It’s not as easy as you might think to study the effect. For one thing, it’s possible that it’s not the physical smile itself, but the request that’s causing the emotional change. Researchers have attempted to get around that problem by simply directing people to move their facial muscles in a proscribed sequence (“Move your lips to expose your teeth while keeping your mouth closed.” “Now use your cheek muscles to pull the corners of your lips outward,” and so on). But still, it’s likely that research participants will catch on to the purpose of the study when they are asked whether they are feeling happy or sad.

In 1988 a team led by Fritz Strack came up with a brilliant cover story that allowed them to manipulate facial expressions without the research participants’ awareness. The researchers told participants that they were studying adaptations for people who had lost the use of their hands. Such individuals would need to use their mouths to hold pencils for writing, or to use a television remote. The study was to assess whether the unpleasantness or difficult of these tasks affected their “attentional abilities and responsiveness.” The current study on people with full use of their hands was simply designed to test the procedure.

The participants then held a pencil in their teeth (which naturally activates the muscles typically used for smiling) or lips (which does not activate those muscles), and then rated several cartoons for funniness. Those who were (unknowingly) “smiling” rated the cartoons as funnier than people who weren’t smiling.

Innovative as it was, the Strack team’s study had several limitations, the most important of which is that the researchers didn’t account for the physical differences in holding a pencil with lips versus teeth. If the people are simply more uncomfortable holding a pencil in their lips, that might explain the entire difference between the “smiling” and “not smiling” conditions.

In 2002 Robert Soussignan designed a new study which both addressed the earlier works’ limitations and added a couple extra twists. He adopted Strack et al.’s cover story, but asked 96 female undergraduates to hold the pencil in one of four different ways: In the lips, in the teeth but without “smiling,” in the teeth while “fake smiling” — exposing the teeth and stretching the corners of the mouth but not raising the cheeks in a more authentic looking smile, and in the teeth with an authentic smile expression. This was done by telling participants to both stretch the corners of the mouth and raise their cheeks. I tried these last two techniques myself:


I think you’ll agree that I look much happier in the picture on the right.

Once participants were coaxed into these positions, they conducted two tests. In the first, a distractor meant to disguise the true purpose of the study, they used the pencil to underline the vowels in a sentence. Then they were shown several video clips and asked to rate their reactions to them on a scale of -9 (negative emotion) to +9 (positive emotion). Some of the clips were very negative, such as a mutilated body or a person stretching an animal skin. Others were mildly positive, like landscapes or baby animals, and others were extremely positive — funny clips from the cartoons Tex Avery and Tom & Jerry. For the positive videos, there was a distinct difference between the ratings of the participants who were smiling and those who were not. Here are the results for the cartoon clips:


The ratings for the authentic smilers were significantly higher than the non-smilers for each cartoon. The Tex Avery cartoon was rated significantly higher for authentic smilers than fake smilers, while there was no significant difference between smile types for the Tom & Jerry cartoon. The moderately positive videos showed an even more dramatic difference, with authentic smilers rating their reactions significantly higher than any of the other three conditions.

Soussignan also asked the participants to rate the unpleasantness of the requirement of holding the pencil during the study, and found no significant differences between any of the conditions. The students also were carefully questioned, and none of them suspected the real purpose of the study.

Interestingly, there was no difference in the ratings of the unpleasant videos between any of the groups. Only positive videos were affected by the smiling / non-smiling condition. Soussignan argues that this supports the notion that smiling will accentuate a positive emotional experience, but will have no effect on a negative experience.

This might also explain why it’s so difficult to get a gloomy teenager to smile.

Soussignan, R. (2002). Duchenne Smile, emotional experience, and automatic reactivity: A test of the facial feedback hypothesis. Emotion, 2(1), 52-74. DOI: 10.1037/1528-3542.2.1.52


  1. #1 Andy
    November 28, 2007

    My teacher tried to do this for us at class–but who wants to put a pencil in their mouth? Gross.

    Very interesting study though, thanks for the link.

  2. #2 Nick Sullivan
    November 28, 2007

    One way to eliminate the bias due to the lip grip being possibly less comfortable than the tooth grip might be to ask the subjects to simply pretend to hold the pencil. My random sample of one found that maintaining this pretence was both easy and effective. Which prompts the thought that, when one is faced with the need to get a group of people to smile simultaneously – as for seasonal photographs – one could do worse than asking them to imagine that they are all holding pencils between their teeth.

  3. #3 John
    November 28, 2007

    I was diagnosed with borderline depression, so I started smiling as much as possible (with the idea that it would make me happier). I am now one of the happiest people I know. I could be an abberation, but try smiling all day, and I think you will find that everything looks prettier, jokes are funnier, and life in general is better. At least, that is my experience.

  4. #4 Andrea Kowalchik
    November 29, 2007

    I have suffered from depression all my life and am an expert at fighting that feeling of hopelessness that comes upon me like a dark cloud even on a sunny day. Years ago I realized that ‘putting’ my face into a smile truly helps. I also use methods like watching old funny sitcoms, and looking at pictures with bright colors with the presence of gold or yellow. I can vouch for the fact that forcing my face into a smile truly works.

  5. #5 Samantha Vimes
    November 29, 2007

    What it seems to show is that having your facial expression match your inner reaction enhances it.
    If it’s HAPPINESS, pictures of kittens and baby ducks will make you at least as happy as funny things. But they make you have more of a warm fuzzy glow than a laughing thing. Similarly, I can laugh when depressed, but it’s a dark laughter that doesn’t help for long, whereas a sense of accomplishment can jolt me off depression towards happiness.

    But a BIG SMILE happens suddenly when you laugh or slowly when you experience large, unexpected satisfaction. Or at least it does with me. Kittens provoke “awwwwww…..”, but provide happiness. Me, I’m more happy with kittens and baby ducks than Tom and Jerry cartoons, and yet holding a pencil in a smile doesn’t enhance the joy of ducklings.

    Nor does it make a sucky experience better, according to the experiment, and people who tell you to “Smile!” are ordering you to ignore your actual sucky situation and pretend to be happy so they don’t have to acknowledge that the world has more states of mind than their tranquility, that they want undisturbed.

    Your teenaged daughter is aware that orders to smile are an attempt to invalidate her emotional state. Brava for her.

  6. #6 Freiddie
    November 29, 2007

    I think this is just another typical psychology experiment where the experimenter lies to the test subjects on purpose. I wonder if I’ll suspect anything when I get the chance to be their Guinea pig.

    On another note, I think smiling does have an effect, because just like there’s a link from happiness to smiling, a reverse link automatically develops from smiling to happiness. This is just like when your teacher tells you that beans are a kind of legumes, you are always reminded of beans whenever you think about legumes.

  7. #7 Dave Munger
    November 29, 2007


    In these cases, research ethics dictates that the researchers debrief the test subjects on the real purpose of the study afterwards. Usually people are happy and interested to learn of a study’s real purpose. Plus they generally either get paid or get course credit for participation.

  8. #8 Freiddie
    November 29, 2007

    I’m glad so. I’m not saying that this ‘lying’ is wrong or anything, but it’s kind of funny to note. But I’m sure the researchers can’t use the same subjects again for the same experiment.

  9. #9 kate
    November 30, 2007

    great post, thanks!
    (and yes, you look much happier in that picture. even with a pen between your teeth)

  10. #10 Andrés
    November 30, 2007

    Is smiling the cause or the consequence of feeling happier?

    I believe it’s an external symbol that comes out naturally if we have a deep heartfelt joy. This joy can be question of a moment or relatively permanent. When it’s relatively permanent, I think it’s a consequence of coherence between our ultimate goals and our actions.

  11. #11 Bill Loomis
    December 1, 2007

    Any great idea in psychology was probably thought of first by William James. The major thesis of Chapter 25 of his Principles of Psychology (1890) is that Emotion Follows Upon the Bodily Expression. The studies here are a particularly clear demonstration of its correctness.

  12. #12 mage ringlerun
    December 2, 2007

    fascinating… absolutely fascinating… i have found that even forcing a smile changes the emotion… even if every so slightly… i think the link between emotion and the physical is two way… and yes, we can choose to change our emotions by manipulating our physical in most cases… that “choosing” might have been an intellectual decision… in my experience… its *all* linked… and when you realise that, you can start to make conscious decisions on your environment that will stimulate other faculties in the order you wish them to be influenced in!

  13. #13 sahiyer
    December 5, 2007

    gr8 study sure i’ll test this in my college aftr d sem holidays n try 2 send u d report

  14. #14 none
    January 14, 2008

    If I genuially smile a lot in the day, I get tired. That’s me though. If I fake smile, which is rare for me, I get even more tired.
