Ron Gutman: Smiling While Confusing Correlation with Causation
There’s a video over at TED that has received over 1.2 million views entitled, The Hidden Power of Smiling by Ron Gutman. It’s only 7 1/2 minutes long, so it’s worth a quick view (below) if you haven’t already seen it.
The premise of the video is simple — smiling can help you lead a happier, healthier life and lead to all sorts of positive outcomes. The research even says so!
The problem? Mr. Gutman has done what a lot of laypeople do — confused correlation with causation, press releases with scientific studies, and interpreted research results in a way the researchers themselves never did.
For good reason — longitudinal and historical research (the type Gutman cites time and time again in his presentation) generally can rarely speak to causation.
So while it’s good for a engaging soundbite at TED (and a followup book), it’s also dead wrong and an example of someone promulgating science at the behest of a “feel good” finding.
So let’s look at the research…
The first study is about a set of researchers1 who had subjects look at yearbook pictures (only of women, by the way), and then examined those yearbook pictures’ subjects 30 years later to see how their lives turned out.
Researchers found that, “Consistent with recent accounts of positive emotion, individual differences in women’s positive emotional expression in their college yearbook photos related to (a) stable aspects of personality and change in certain traits over time, (b) observers’ judgments of the women’s personalities and their responses to these women, and (c) life outcomes measured up to 30 years later.”
That’s cool and all. But nowhere did the researchers mistake a smile for causing the positive life outcomes 30 years later:
Finally, the nature of the longitudinal design allowed us to say little about the specific processes by which positive emotional expression influences the life course.
Indeed, it’s fairly ridiculous to even suggest that a researcher could account for all possible alternative variables, and narrow it down to, “Women who smiled the most were happiest 30 years later, therefore the smile caused or directly contributed to women’s happiness.”
Next up is Gutman’s reference to the 2010 study2 that looked at baseball cards and how long the players lived. Researchers found those players with the biggest smiles lived the longest, which Gutman faithfully notes:
The researchers found that the span of a player’s smile could actually predict the span of his life.
What the researchers actually found is a simple correlation between a photograph’s smile and the player’s longevity. Since a baseball photograph — like a yearbook photo — is a staged photograph, it’s hard to understand what this might have to do with real life, and spontaneous, natural smiling.
It’s not like someone who forces themselves to smile is going to add years on to their life. It’s the underlying emotional disposition, which the researchers themselves made sure to emphasize:
To the extent that smile intensity reflects an underlying emotional disposition, the results of this study are congruent with those of other studies demonstrating that emotions have a positive relationship with mental health, physical health, and longevity.
Smiling itself isn’t the key factor — it’s what the smile represents in the underlying person. If you’re unhappy and look at this video and think, “Wow, if I just force myself to smile more often, I’ll be better,” you’re going to be in for a sorry disappointment.
Gutman nears the end of his talk by referring to a “study” conducted by the British Dental Health Foundation and conducted by HP, maker of digital cameras and photo printers (neither of which he mentions in his talk). This study — never published in a journal and going solely from a press release on a website — purportedly found that a smile is “worth” 2,000 bars of chocolate or £16,000 in cash. Gutman is happy to just repeat these data, without any critical analysis. Because, after all, they make for a good, sexy TED presentation.
Last, he ends with the findings from a 10-year old book about the therapeutic effects of smiling.3 Even if we believe everything this book says, it’s all based upon voluntary, spontaneous smiling — not forcing yourself to smile because you know it may be “healthier” for you.
There are also tons of research on smiling specifically related to age and gender that Gutman couldn’t cover (given his time constraints), but which clearly suggest that the research is a little more complex than, “Smiling will help improve your life.”
Furthermore, none of the studies Gutman cites have been replicated. This means their results are not scientifically robust — certainly not so robust one should be detailing them to a general audience as a guidebook to the way you should live your life.
I can’t help but wonder if this video couldn’t have been more accurately entitled, “Happy people — who tend to naturally smile more — have better, longer lives” — something any psychologist could’ve told you in the first place.
I’m sure Ron Gutman is a good, well-meaning guy. He comes across as someone who is likeable and enjoys smiling. But from his presentation, he also suggests a simple reading of the research that confuses peer-reviewed journal research with press releases, and correlation with causation — basic but serious flaws that undermine his entire message.4
Because smiling is simply a symptom of happiness and well-being — not the other way around.
- Harker, LeeAnne Keltner, Dacher (2001). Expressions of positive emotion in women’s college yearbook pictures and their relationship to personality and life outcomes across adulthood. Journal of Personality and Social Psychology, 80, 112-124. [↩]
- Abel, Ernest L. Kruger, Michael L. (2010). Smile intensity in photographs predicts longevity. Psychological Science, 21, 542-544. [↩]
- Abel, Millicent H. Hester, Rebecca. (2002). The therapeutic effects of smiling. In: An empirical reflection on the smile. Abel, Millicent H. (Ed.); Lewiston, NY, US: Edwin Mellen Press, 217-253. [↩]
- Here’s a tiny side-note as well. The HealthTap blog used to allow comments, and I actually commented on this entry after it was published. But the entry is now devoid of any comments, which I can’t help but be disappointed by. [↩]
Grohol, J. (2012). Ron Gutman: Smiling While Confusing Correlation with Causation. Psych Central. Retrieved on August 1, 2015, from http://psychcentral.com/blog/archives/2012/08/19/ron-gutman-smiling-while-confusing-correlation-with-causation/