Take a look at this video (QuickTime required). The screen will turn white for 1/2 second. Then a word will appear for about 1.5 seconds. Pay attention to the particular shade of gray the word is printed in. Next, a strip of five different grey squares will appear. Which square matches the color of the word?

It’s a difficult task, but not impossible (we’ll collect answers in a poll at the end of the post). A team led by Brian P. Meier had college student volunteers complete a similar task, and they were able to achieve 30 percent accuracy — somewhat better than the 20 percent you would expect if they were choosing randomly. But as you might guess, the researchers weren’t primarily interested in how accurate the viewers were. What they wanted to know is if the word itself influenced the students’ choice of color.

In 1999 the controversial linguist George Lakoff and philosopher Mark Johnson argued that metaphors used in language can actually affect our perceptions. Indeed, metaphors of “light” and “dark” are frequently used by politicians to represent good and evil. But Lakoff and Johnson’s research is typically applied only to linguistic meaning. Can it also apply to visual cognition? In 2004 Meier led a team which found that viewers were faster and more accurate categorizing positive words when the letters were white, and better categorizing negative words when the letters were black.

In a new set of experiments, Meier’s team wanted to see if the process worked in reverse.

First they showed viewers 50 positive words (“love,” “baby”) and 50 negative words (“rude”, “spider”), in random order. After viewers said whether the word was “positive” or “negative,” they were shown a gray square, but they were told they were being shown one of two slightly different squares. The task was to say whether they were seeing the lighter or darker square (in fact there was only one square). Viewers were significantly more likely to say they had seen the dark square after negative words, and more likely to say they had seen the light square after positive words.

But perhaps describing the squares as “lighter” or “darker” biased the viewers, and their responses reflected not what they saw, but simply the difference in meanings of the words they had read. In a second experiment, the researchers presented the words using a display similar to the movie above. Viewers had to say whether the meaning of the word was “positive” or “negative.” The words could be one of three different brightness levels, which matched exactly with one of the squares that followed. Next viewers used a mouse to click on the square that was the same color as the word they had just seen. Viewers were more likely to click on a lighter-colored square after seeing a positive word, and more likely to click on a darker-colored square after seeing a negative word.

But arguably these experiments still don’t show that we automatically perceive positive and negative words in terms of light and dark. In one final experiment, positive or negative words were flashed on screen for a quarter of a second. Viewers were not required to categorize the words as positive or negative. Then one of two grey squares appeared, and viewers had just 4/10 of a second to identify the squares as light or dark. These squares, unlike the previous squares, were easily distinguishable:

So, how did the meaning of the word affect accuracy? Here are the results:

Viewers were significantly more accurate identifying the light square after seeing a positive word, and significantly more accurate identifying the dark square after seeing a negative word.

Meier’s team argues that these studies demonstrate that the metaphors of light and dark are automatically associated with positive and negative words. They suggest this association may be due to the fact that humans are normally active during the day. Since we prefer the light, then light colors are naturally associated with positive emotions.

By the way, how did you do on the demo? Here’s a poll to record your responses:

I’ll give the correct response later today in the comments.

Meier, B.P., Robinson, M.D., Crawford, L.E., & Ahlvers, W.J. (2007). When “light” and “dark” thoughts become light and dark responses: Affect biases brightness judgments. Emotion, 7(2), 366-376.