Red scare, quite literally

The color red is commonly used to caution us. Used prominently in alerts ranging from stop signs to warning labels, we generally associate red with some kind of threat or danger. Some have even suggested that athletes whose team color is red dominate more than those with other team colors (although having been a Stanford Cardinal during a period of particularly embarrassing athletic performance, I have my doubts).
In any case, the roots of this phenomenon are interesting from an evolutionary psychological perspective—is our association between a color and certain emotions hardwired or culturally based (or a mix of both)? Researchers at Dartmouth have reason to believe the former. In an upcoming Psychological Science paper (see here for more details), they describe the results of a recent study that uses the behavior of rhesus macaque monkeys to infer the evolutionary basis of our associations with the color red.

The research team approached the primates and offered them apple slices, measuring how often the macaques actually took the slices from the tray. The only factors varied were the color of the experimenter’s clothing (red, green, or blue) and experimenter sex. As it turns out, sex had no effect—macaques accepted apples from male and female experimenters equally. However, they were much less likely to take the apple when the experimenter was wearing red than when he or she was wearing another color.

According to the authors, these results suggest that the connotation of threat we assign to the color red is innate, evident even in our evolutionary relatives. However, what this study doesn’t tell us is why. What is it about red that essentially scares us into submission?