Key concepts

Have you ever wondered if your preferences bias the choices you make? You make choices all the time, whether you are aware of them or not. Many different factors probably work together to affect the option you end up choosing. Which do you think are the most important?

Everyone has personal preferences, and these may affect the choices we make. What about your favorite color? You may prefer one color over another for no good reason, other than the fact that you like it—or you may have a personal reason for choosing a certain color. Do you think a color preference will affect your choices?

Might color preferences have biological origins? When we see a color, it is interpreted in our brain by the visual cortex, where different groups of neurons are stimulated. These different stimulations of neurons within the visual cortex might lead to color preferences, which might, in turn, affect our behavior.

While processing visual information, such as the perception of different colors, our brains also coordinate our muscle movements. This occurs in the brain's motor cortex. The visual cortex and motor cortex in our brains must function well together to allow for proficient hand-eye coordination. For example, when you catch a fast-moving ball, your eyes must tell your brain where the ball is, and then the brain tells your arm and hand muscles to make movements to catch it. Because the motor cortex must work so closely with the visual cortex, visual preferences, such as a favorite color, may affect movements and behaviors.

•    Bag of M&M's (at least 12.6-ounce size)
•    Bowl
•    An extra volunteer or two participants (the more the better)
•    Paper
•    Pencil or pen

•    Pour out the bag of M&Ms and count out 50 of each color.
•    Combine 50 M&Ms of each color in a bowl.  Mix them together.

•    Place one arm behind your back, and pick out candies as quickly as possible using only a two-finger pinch. As the candies are pulled out, place the selected ones on the table next to the bowl. Stop when you have pulled out 20 candies.
•    Write down the name of your favorite color. Then write down the total number of each M&M color that you pulled out. Return the pulled M&Ms back to the bowl. Was the M&M color you chose most the same as your favorite color?
•    To make this activity even more scientific, repeat the procedure with other volunteers—and do not tell them what you are testing until after they have selected their candies from the bowl.
•    Write down everyone's color preference and the number of each color of candy that they selected. If their favorite color is one that is not in the M&M bowl, ask them instead which of the colors of the M&M's they like best.
•    For each favorite color group, calculate the percentage of M&M's chosen of each color. For example, if three participants said blue was their favorite color, and together they pulled a total of 18 blue M&M's, out of a total of 60, then you would calculate that 30 percent of M&M's picked by this group were blue. If people have no color preference, and there is approximately an even distribution of the six colors of M&Ms in the bowl, what percentage of the time would you expect each color to be selected?
•    Did your participants tend to pick their favorite color? Within each favorite color group, was there a color that was the second-most frequently picked one? What was the most frequently picked color overall?
•    Extra: Try this experiment to test how preference affects choice in younger children. Ask a small child to choose a stuffed animal from an assortment of stuffed animals. Then ask what his or her favorite real animal is. Repeat this with multiple small children. How many times does their favorite animal match the stuffed animal they chose?
•    Extra: You can also try experiments to test mind-body coordination with handedness. Will people tend to use the same hand with wich they write to pick something up? Will people tend to step out first with the same side that they write with? To make these activities the most reliable, explain what you are testing only after volunteers have completed the procedure—otherwise they might change their behavior based on what they think they are expected do.

Observations and results
Did participants tend to pick their favorite color? Was one M&M color picked much more frequently than the others?

Preferences affect the quick choices we make all the time. What our favorite color is might be no exception. You might have seen participants tend to pick M&M's that matched their favorite color. However, if a participant had chosen a certain color as his or her favorite not because the participant thought it was the most attractive color, but for other reasons such as a personal experience, the participant might not tend to pick M&M's that matched his or her stated favorite. In addition to favorite color, other factors may also affect color selection, such as colors preferred in food, temperature or lighting. What other considerations do you think affect your choices?

More to explore
"Favorite Colors: Color Preferences Determined by Desirability of Objects" from Scientific American
"Color Changing Dots" from Scientific American
Our Sense of Sight: Part 3: Color Vision from Marjorie Murray, at the University of Washington in Seattle
Do Preferences Bias Our Choices? from Science Buddies

This activity brought to you in partnership with Science Buddies