I dragged nine year-old Isaac to see my friend Kevin Gould giving a professorial address a couple of months ago. He is an internationally respected botanist and one of New Zealand’s best teachers, so taking Isaac along was less of a risk than it might sound.
The talk focused on some of the characteristics of the pigments that give plants their colour, and one particular family of pigments, anthocyanins, that are responsible for the red, purple and blue colour of numerous plants, fruits and veges.
So, what’s this got to do with psychology? Well, anthocyanins have antioxidant properties that have potential health benefits for humans, but in plants they have a protective function. For example, the native horopito (sometimes called the pepper tree) has red splotches on the leaves – caused by anthocyanins – and they’re a signal to anything hungry to avoid them.
Gould summarised some research concerning the colours we like most (blues) and least (browns). It has been hypothesised that this is an evolved response – blue is associated with things that are safe and pure (blue water, for example), whereas brown isn’t as popular because, well, “’Cos it looks like pooh, Dad,” says Isaac.
This means a sumptuous buffet will look a lot less appetising if you mess with the colours. But these colour effects don’t only apply to food. If you’ve seen the otherwise fun computer-generated movie The Polar Express, you may have had the same reaction as some reviewers: the animation is realistic, but there’s something a bit off about the characters. Their flesh tone is not quite right, and some research suggests this triggers disquiet because we interpret that not-quite-right tone as a sign of illness. For instance, one study has shown that primates react negatively to pictures of other primates in which the colour of the skin has been subtly altered.
I’m fond of talking about research that shows we see sports teams dressed in black as more aggressive than those in paler colours, and that players feel more aggressive and powerful, too. Research like this has important implications for sporting tradition.
Naturalistic tests of the impact of uniform colour are tricky. For example, we can’t know how the All Blacks would have played in that 2008 game against France if they had been wearing their usual black. But there are some sports where we can do the next best thing.
In a 2005 paper published in Nature, authors Russell Hill and Robert Barton analysed performances of competitors in tae kwan do, boxing and Greco-Roman and freestyle wrestling in the 2004 Olympics. Unlike competitors in many other events, those athletes in one-on-one sports don’t wear national colours but are instead randomly allocated red or blue. As allocation is random, it shouldn’t affect the results, right? But there was a difference.
You will already have guessed that red wins statistically more than you’d expect by chance alone – red showed an advantage every time, between 4% (Greco-Roman) and 14% (tae kwan do). Hill and Barton noted that, in nature and biology, red is associated with physiological arousal, aggression and displays of dominance, whereas blue is seen as an indicator of coolness and calm. So, deep in the recesses of ancestral memory, the blue-clad athlete cowers in front of the display of dominance of his or her red-clad opponent. Or so the story goes.
More recently, Norbert Hagemann, from the University of Kassel, and some colleagues have suggested another possibility. Using graphics software, they manipulated the same clips of tae kwan do bouts and asked experienced referees to allocate points to the competitors. The referees consistently allocated more points to competitors clad in red than they did to the same competitors when they were wearing blue. It’s not so much the effect on the competitors, they suggest, but the effect on the referees.
All Reds, anyone?