LoBue and DeLoache presented 192 boys and girls aged between seven months and five years with pairs of small objects (e.g. coasters and plastic clips) and invited them to reach for one. Each item in a pair was identical to the other except for its colour: one was always pink, the other either green, blue, yellow or orange. The key test was whether boys and girls would show a preference for choosing pink objects and at what age such a bias might arise.

At the age of two, but not before, girls chose pink objects more often than boys did, and by age two and a half they demonstrated a clear preference for pink, picking the pink-coloured object more often than you’d expect based on random choice. By the age of four, this was just under 80 per cent of the time – however there was evidence of this bias falling away at age five.

Boys showed the opposite pattern to girls. At the ages of two, four and five, they chose pink less often than you’d expect based on random choices. In fact, their selection of the pink object became progressively more rare, reaching about 20 per cent at age five. Analysis from one trial to the next showed this wasn't simply due to boys growing bored of the pink choice - they avoided pink items from the beginning of their participation.

A second experiment zoomed in on the age period of two to three years, to see how colour preferences changed during this crucial year. The same procedure as before was repeated with 64 boys and girls in this age group. Among the children aged under two and a half, both boys and girls chose pink objects around 50 per cent of the time, just as you’d expect if they were choosing randomly and had no real colour preference. Among those aged between two and a half to three years, by contrast, the boys showed a bias against choosing pink and the girls showed a bias in favour of pink.

“This research lends important information to when children develop gender-stereotyped colour preferences …” the researchers said. “Knowing exactly when children begin to demonstrate these tendencies can help lead to fuller understanding of the development of gender-stereotyped behaviour more generally and can be an important marker for future research in this domain.”

LoBue, V., and DeLoache, J. (2011). Pretty in pink: The early development of gender-stereotyped colour preferences. British Journal of Developmental Psychology, 29 (3), 656-667 DOI: http://dx.doi.org/10.1111/j.2044-835X.2011.02027.x

Author weblink: http://psychology.rutgers.edu/~vlobue/#research

From BPS research digest