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Psychology of Red

August 15, 2012

The color, red, evokes some stereotypes. Red is the color of danger, presumably because it's the color of blood. That's probably why we have red stop lights and red stop signs. There's also the idea that bulls are attracted to the matador's cape because it's red. All cattle, including bulls, are colorblind, so the color is irrelevant. The actual reason is because the cape is a large, moving object.

Scientists know that red is a bad color choice for an object you want to be seen. The human eye sees green objects much better than red objects (see figure). So, should our red stop lights and red stop signs actually be green? These exist in a background environment that's mostly green, at least in areas where trees are still allowed to grow, so red is probably still a good color choice for contrast's sake.

Eye color sensitivity

Color sensitivity of the human eye.

The way you develop such a curve is by asking study participants to equalize the perceived intensity of various pairs of colored lights, and then churning through the math.

(Via Wikimedia Commons, modified))

There is another, more technical, reason for using red light in a warning beacon. Rayleigh scattering, which is the scattering of light as it propagates through the atmosphere, is somewhat less for the longer wavelength red light than shorter wavelength blue and green light. There's only a factor of two difference in scattering over the visible color range, but every bit helps.

The physical properties of red are very easy to state. Red is just that portion of the electromagnetic spectrum between 630 and 700 nanometers. When we ask about the human sensation of red, the "quality of redness," we've opened up a philosophical discourse that I mentioned in a previous article (The Quality of Chairness, December 3, 2010).

The psychological properties of red have been studied extensively. Experiments by psychologists at the University of Rochester have shown that men are attracted to women wearing red, and vice versa.[1-3] Other Rochester experiments have shown that humans react more forcefully and more quickly when they see red, but they have no idea that the color has affected them.

In one experiment, undergraduate students squeezed a handgrip as hard as possible whenever they saw the word, "squeeze," on a computer display. The word was displayed on a red, gray or blue background. A red background caused a significant increase in the exerted force and the speed of their response.[4-5] I wrote about these experiments in a previous article (Power Tie, June 9, 2011).

Red 'power' tie

Power Tie

Businessmen believe that a red necktie advertises power.

Psychological studies indicate they may be correct.

(Via Wikimedia Commons, modified))

The logo of my former employer is entirely red. The Wikipedia page for "Red" lists seventy-seven major companies with red in their logos, from Avis to Wendy's, and Kmart in between. Perhaps the reason I don't get much business is because my logo is blue.

It comes as no surprise that those red logo companies and many others are using psychology to sell more products at higher prices. One article in the Journal of Consumer Research focuses on the power of the color, red, as a tool for greater profitability.[6-7]

In an online auction, a red background will cause bidders to act more aggressively and make higher bids. However, when a person was not in competition with a corp of online bidders, but rather just dealing with a seller in a one-on-one basis, a red background reduced the willingness to buy a product, but a blue background caused the buyer to offer a higher price.[6]

One study, at the Cornell University Food and Brand Lab showed that placement of red potato chips at intervals in tube-type potato chip containers acted as a subconscious signal to stop eating. College students, who were the study subjects, ate about half as many chips when the red chips were present.[8-10]

Said Brian Wansink, director of the Cornell University Food and Brand Laboratory,
"People generally eat what is put in front of them if it is palatable... An increasing amount of research suggests that some people use visual indications, such as a clean plate or bottom of a bowl, to tell them when to stop eating."[8]

Another article in Journal of Consumer Research showed that consumers are more likely to choose a product in the lateral center of a display case.[11-12] This is an important result, since it affects everything from items in a vending machine to vitamins in a health food store. The research was done using eye-tracking devices that found that consumers tended to focus on the display center in the final five seconds before making a choice.[12]

In the spirit of "forewarned is forearmed," next time I'm in the supermarket I'll try to give equal time to those lonely products at the edge of the shelves.


  1. Susan Hagen, "Psychological Study Reveals That Red Enhances Men's Attraction to Women," University of Rochester Press Release, October 28, 2011.
  2. Liz Hurley, "Wearing red 'boosts attraction'," BBC News, October 28, 2008.
  3. Susan Hagen, "Women Attracted to Men in Red, Research Shows," University of Rochester Press Release, August 2, 2011.
  4. Susan Hagen, "Color Red Increases the Speed and Strength of Reactions," University of Rochester Press Release, June 2, 2011.
  5. Andrew J. Elliot and Henk Aarts, "Perception of the color red enhances the force and velocity of motor output," Emotion, vol. 11, no. 2 (April, 2011), pp. 445-449.
  6. Mary-Ann Twist, "Selling on eBay? Get higher bids with a red background," University of Chicago Press Journals Press Release, July 16, 2012.
  7. Rajesh Bagchi and Amar Cheema. "The Effect of Red Background Color on Willingness-to-Pay: The Moderating Role of Selling Mechanism." Journal of Consumer Research: February 2013.
  8. Sandra Cuellar-Healey, "Red potato chips: Segmentation cues can substantially decrease food intake," Cornell University Food and Brand Laboratory Press Release, July 24, 2012.
  9. Rachel Eklund, "Will you eat less if your food had “STOP” signs?," Cornell University Food and Brand Laboratory, February 21, 2012.
  10. A. Geier, B. Wansink & P. Rozin, "Red potato chips: Segmentation cues can substantially decrease food intake," Healthy Psychology, Vol, 31, no. 3 (May 2012), pp. 398-401..
  11. Mary-Ann Twist, "Are consumers aware that they are drawn to the center when choosing products?" University of Chicago Press Journals Press Release, July 16, 2012.
  12. A. Selin Atalay, H. Onur Bodur, and Dina Rasolofoarison. "Shining in the Center: Central Gaze Cascade Effect on Product Choice." Journal of Consumer Research: December 2012.

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