You could argue that it doesn’t really matter what colour babies are exposed to the most, but it can even affect the way we, as adults, treat them. There’s one famous study showing that women treated the exact same babies differently depending on whether they were dressed in pink or blue. If the clothes were blue they assumed it was a boy, played more physical games with them and encouraged them to play with a squeaky hammer, whereas they would gently soothe the baby dressed in pink and choose a doll for them to play with.

Pink for boys?

But what about the idea that a century ago little boys were dressed in pink and pink for girls is only a recent fashion? It seems even that might be something of a myth too. Psychology writer Christian Jarrett describes in his new book Great Myths of the Brain, how an Italian psychologist Marco Del Giudice, who tried to find the origins of this idea, could find just four short magazine quotes, describing pink as the colour for boys. In two of these he believes that perhaps the blue and pink were accidentally swapped around. That seems unlikely to me, but when he searched a database of five million books printed in American or British English from 1800-2000 more convincing was the lack of any mentions of “pink for a boy”, even though from 1890 onwards there were increasing mentions of “pink for a girl”.

Even the association of pink with femininity today can backfire if it’s not used in the right way. Pink is often used for breast cancer campaigns, but researchers at Erasmus University Rotterdam found that when women were shown adverts dominated by the colour pink, they were in fact less likely to think they’d contract breast cancer themselves or to donate money to a cancer charity. The authors don’t believe this was because they hated the colour pink, but because when they were reminded of their gender so overtly, the adverts felt so personally threatening that it set off denial mechanisms.

But there is one way at least in which pink can be useful for both women and men. Back in 2002 researchers in Switzerland who were keen to increase the response rate to surveys, found that printing questionnaires on coloured paper made no difference, unless the paper was pink, in which case 12% more people filled it in.

Colours, it seems, influence our behaviour much more than we realise.

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