Does Reading Words About Old Age Really Make You Walk Slower?

In 1996, psychologist John Bargh published an experiment in which forming sentences with words related to old age made twenty-year-old students walk more slowly. It became known as the “Florida effect” and turned into the classic example of what psychology calls priming: the idea that exposure to a concept predisposes us, without our noticing, to think or act in ways consistent with it. Daniel Kahneman devoted several pages to it in Thinking, Fast and Slow (2011).

The short answer to the question in the title is probably not: later, more rigorous replications haven’t confirmed the effect. But the experiment, how it was told and why it failed teach a lot about how psychological science works, which is why it’s worth explaining in full.

The experiment: forming sentences from loose words

Bargh asked students at New York University, most of them between eighteen and twenty years old, to form four-word sentences from a set of five terms they were handed (for example: “yellow, finds, he, it, instantly”).

The exercise looked like a simple language test.

What the students didn’t know is that, for half of them, many of those word sets included terms culturally associated with old age:

• Florida
• forgetful
• bald
• gray
• wrinkle

None of those words meant “old” explicitly; it was enough that they evoked the idea indirectly.

After finishing the task, each student was sent to another office a little farther away, down a hallway.

That brief walk was, in fact, the real point of the experiment: the researchers timed, without the participants knowing, how long each one took to cover it.

The finding: walking slower without knowing why

The students who had formed sentences with words related to old age walked more slowly to the second office than the others.

The difference wasn’t dramatic.

Bargh had predicted it in advance, precisely because old age is culturally associated with physical slowness, and his hypothesis was that simply activating the idea of “old age” would be enough to indirectly activate the behavior of “walking slowly,” without ever passing through a conscious thought like “now I should walk more slowly.”

When participants were later asked whether they’d noticed anything in the sentence exercise, none identified the shared theme of the words, and all insisted that nothing that happened afterward could have been influenced by that first task.

That was the conclusion of the original study: the idea of old age supposedly never reached the participants’ conscious minds and yet shaped the way they walked a few minutes later.

Two linked stages

Kahneman describes this mechanism as a two-step sequence:

• First stage: the set of words activates, in associative memory, the general idea of old age, without the word “old” ever needing to appear.
• Second stage: that idea, once activated, in turn predisposes a behavior culturally associated with it (walking slowly), again without conscious involvement.

This kind of influence of an idea on a physical action is called the ideomotor effect.

Kahneman notes, with some humor, that the reader of his book may have been slightly primed after reading the paragraph about the experiment: if at that moment they felt the urge to get up for a glass of water, they probably did it a little more slowly than usual.

The link also works in reverse

A study conducted at a German university replicated the idea, but reversed the order of cause and effect.

Instead of activating an idea first and then observing a behavior, a group of students was asked directly to walk around a room for five minutes at a deliberately slow pace, about a third of normal speed.

After that brief physical exercise, those same students recognized words related to old age faster, such as “forgetful,” “old” or “lonely,” than a control group did.

Kahneman presented this as proof that the link between idea and behavior runs both ways. It’s a single study with a small sample, and today it’s read with the same caution as the rest of the research on behavioral priming.

Kahneman calls this kind of reciprocal connection part of the associative network, the same network that means having fun tends to make us smile, and smiling, even without any real reason to, tends to put us in a better mood.

The pencil-between-the-teeth experiment

The book includes another experiment that illustrates the same principle even more strikingly.

In the study by Fritz Strack, Leonard Martin and Sabine Stepper (1988), a group of students held a pencil in their mouth in two different ways: between the teeth, which pulls the facial muscles into a position similar to a smile, or between the lips, which prevents smiling.

Without anyone saying anything about facial expressions, they were asked to rate how funny some cartoons by Gary Larson were.

Those holding the pencil in the way that forced an involuntary “smile” rated the cartoons as funnier than those holding it the other way.

In a related experiment, people who were made to adopt an angry expression (by furrowing their brow) showed a more intense emotional reaction to harsh images, such as scenes of malnourished children or accidents.

What happened when people tried to repeat them

Since they were published, several of these experiments have been repeated with larger samples, and they haven’t always held up.

• The Florida effect. In 2012, Stéphane Doyen and his team repeated the old-age study with automatic timers and a larger sample, and found no evidence that participants walked more slowly. An effect only appeared when the people doing the measuring believed participants would walk more slowly, which points to the researchers’ expectations as part of the explanation.
• The pencil between the teeth. In 2016, a project coordinated across 17 labs did not reproduce the effect from Strack’s study. In 2022, a collaboration with 3,878 participants from 19 countries (Coles et al.) found that mimicking a smile or adopting one voluntarily did increase feelings of happiness, but that with the pencil technique the results were inconclusive.

Kahneman himself later acknowledged that he had placed too much faith in small-sample priming studies. That’s why the Florida effect is now considered an unconfirmed hypothesis, and facial feedback a real effect, but one that is more modest and more dependent on method than was once thought.

What this says about our decisions

The fact that the Florida effect doesn’t hold up doesn’t invalidate Kahneman’s broader point: many of our judgments rest on fast, automatic associations. What changes is the scale. Associations influence how we interpret information, but there’s no solid evidence that a list of words is enough to change the way someone walks.

That distinction between fast, associative judgments and slow, deliberate ones connects with the intuitive style, which trusts first impressions, as opposed to the analytical profile, which prefers to slow down and gather data before deciding.

If you’re curious about your own decision-making pattern, the decision-making style quiz is a good place to start.

Sources

• Kahneman, D. (2011). Thinking, Fast and Slow. Farrar, Straus and Giroux.
• Bargh, J. A., Chen, M. and Burrows, L. (1996). Automaticity of social behavior: Direct effects of trait construct and stereotype activation on action. Journal of Personality and Social Psychology, 71(2), 230-244.
• Mussweiler, T. (2006). Doing is for thinking! Stereotype activation by stereotypic movements. Psychological Science, 17(1), 17-21.
• Strack, F., Martin, L. L. and Stepper, S. (1988). Inhibiting and facilitating conditions of the human smile: A nonobtrusive test of the facial feedback hypothesis. Journal of Personality and Social Psychology, 54(5), 768-777.
• Doyen, S., Klein, O., Pichon, C.-L. and Cleeremans, A. (2012). Behavioral priming: It’s all in the mind, but whose mind? PLoS ONE, 7(1), e29081.
• Wagenmakers, E.-J. et al. (2016). Registered Replication Report: Strack, Martin, & Stepper (1988). Perspectives on Psychological Science, 11(6), 917-928.
• Coles, N. A. et al. (2022). A multi-lab test of the facial feedback hypothesis by the Many Smiles Collaboration. Nature Human Behaviour, 6(12), 1731-1742. https://doi.org/10.1038/s41562-022-01458-9