(Inside Science) -- Seeing red commands our instant attention. On stop signs or warnings, the color raises our level of attentiveness or alerts us to potential dangers. Red lipstick or red roses, on the other hand, have a come-hither effect on many.
Does the color signal attraction or avoidance? Red can be both, depending on context, suggest psychologists who study how color affects our behavior.
When asked to categorize faces with different expressions as either happy or angry, women identified angry expressions more quickly when the faces were on a red background, compared to green or grey. Behind happy faces, red had the opposite effect. Participants in this study identified happy faces quickest when on a green background, and took the longest time to process the faces when they were against a red backdrop.
Earlier research has found that people identify happy expressions more quickly than they do other emotions. A red background seems to eliminate this "happy face advantage," according to this research, published in the journal Emotion in June.
Watch that tip when you dine at a holiday-themed restaurant. People might tip red-clad servers less, according to a new study published in the Journal of Hospitality and Tourism this September.
The researchers showed people pictures of male and female servers wearing red, white or black, presented them a check for $15.86 and then asked how much they would tip. The hypothetical red-clad waitstaff received significantly less, on average, than those who wore white or black.
The study contradicts earlier work where researchers observed men in restaurants tipping waitresses who wore red more than those who wore shirts of other colors.
Winning a combat sport may be, in part, about the right color. Male athletes who wore red jerseys and played against men in blue had heart rates approximately 7 beats per minute higher than their opponents during an experimental combat sport. Men who wore red also performed better on a pre-combat test of strength. The results stayed the same when the men switched outfits colors and played a second round– those in red fared better on both measures.
In the 2004 Olympic Games in Athens, Greece, researchers found that athletes wearing red won significantly more often in the boxing, taekwondo and wrestling events than those wearing blue. The effect was only seen when the competitors were closely matched in ability. But it wasn't clear whether the psychological impact of color was on athletes' performance, or referees' decision-making. A previous study correlated this observation to a difference in the referees' judgment. This new study, published in the Journal of Sport and Exercise Psychology in February, suggests the opposite; the difference stems from participants' physiological functions.
Retail red herring
Bright stickers advertising promotions and discounts might influence how you shop. Male shoppers presented with an ad for special prices on toasters and microwaves were more likely to splurge when prices were in red rather than black. The red prices seemed to put buyers in a happier frame of mind, enhancing the savings they perceived in the purchase. The effect faded, however, when shoppers were more involved in the task and paid close attention to the numbers. In this particular study, published in the Journal of Retailing in June, the effect was also gender-specific – women were less easily lured by a bargain in a red font. The researchers suggest the effect might extend to other colors of a similar wavelength, such as orange.
Choose your font colors wisely -- people remember words in certain colors better than other words, particularly if they have an emotional connotation. Researchers tested volunteers' recall of neutral or emotional words printed in black, blue, red and green. Red strongly increases the memory of negative words; people recall positive words in green more readily. Neither black nor blue had effects on how well people recalled words linked to emotions. The study, published this June in the journal Emotion, supports the idea that certain colors influence the strength of some emotion-related memories. The researchers suggest that since red is seen as desirable in other contexts, recall of some positive words, related to attraction, might be enhanced by the color.
One color, two ways
A mixture of environmental cues, biological impulses and individual experience trigger our motivations. Studying how a color like red fits into this complex mix is complicated, as many psychology researchers note.
It may not be time to re-color the holidays to something besides red, but think twice before you react to an eye-popping red this season.
Jyoti Madhusoodanan is a science writer based in San Jose, Calif. She tweets at @smjyoti