Melissa Hines

Who they are

Hines holds a BA in Psychology from Princeton University and a PhD from the University of California, Los Angeles. According to her Cambridge department profile she was a postdoctoral fellow in neuroendocrinology and neuroscience at the UCLA Brain Research Institute and a visiting scientist at the Primate Research Centre of the University of Wisconsin, Madison. She held academic posts at the University of London, City University London and UCLA's Department of Psychiatry and Biobehavioral Sciences before joining Cambridge in 2007.

At Cambridge she is Professor of Psychology and Director of Graduate Education in the Department of Psychology, and a Fellow of Churchill College. She leads the Gender Development Group. Her research areas, as the profile lists them, are hormonal influences on neural and behavioural development, including translational animal models, gender development across the lifespan, the interaction of prenatal influences with postnatal experience on brain and behaviour, and the study of people who were exposed to unusual prenatal hormone environments.

Her journal articles have appeared in Annual Review of Neuroscience, Child Development, Developmental Psychology, Journal of Neuroscience, Psychological Science and Psychological Bulletin, and she is the author of the book Brain Gender, published by Oxford University Press in 2004. She received the Shephard Ivory Franz Award for Distinguished Teaching at UCLA. Her public engagement has included television and radio appearances on gender development and a talk at the 2014 Cambridge Science Festival.

Key papers

Wong and Hines (2015), 'Preferences for pink and blue: The development of color preferences as a distinct gender-typed behavior in toddlers', Archives of Sexual Behavior 44(5), 1243-1254. It was a longitudinal study of 126 toddlers with a mean age of 29 months at the start (range 20 to 40 months), tested twice, six to eight months apart. Colour preferences were measured with colour cards and with neutral toys recoloured in gender-typed colours. Toy and activity preferences were measured by parent report on the Preschool Activities Inventory, and parents also completed the colour card task.

A companion paper by the same authors, 'Effects of gender color-coding on toddlers' gender-typical toy play', studied 56 boys and 70 girls aged 20 to 40 months at the first testing, with 40 boys and 59 girls retested at 26 to 47 months. The toddlers played with a train and a doll, each presented in a gender-typical and a gender-atypical colour. Boys played more with the train, and girls more with the doll and with pink toys. Boys and girls combined played more with the toy typical of the other sex when its colour matched their own sex, and the gender differences in toy preference were larger in gender-typical colours.

Hines is also a co-author of the 2010 infant study by Jadva, Hines and Golombok on preferences for toys, colours and shapes, which used a looking task with 120 infants aged 12, 18 or 24 months and found no significant sex differences in colour or shape preferences, with both sexes preferring reddish colours over blue. This page read the paper's abstract, not its full text.

Key ideas

The 2015 toddler study separates two things that are usually bundled: a child's liking for gender-typed toys and activities, and a child's liking for gender-typed colours. A sex difference in colour preference appeared between ages two and three and grew stronger close to the third birthday, when it was large, with an effect size above 1, meaning the group averages sat more than one standard deviation apart. The toddlers' colour preferences were stronger and less stable than their parents' preferences, emerged later than their toy and activity preferences, and were largely uncorrelated with them.

The authors drew a modest conclusion. The two kinds of preference appear to be shaped partly by different factors. They suggested that social and cognitive influences contribute to colour preferences, along with play with gender-typed toys that happen to come in gender-typed colours. The result sits beside a 2011 experiment on 192 children that found the pink split opening between two and a half and three, and the two sets of findings are summarised on the page for gender-typed colour preference.

For readers weighing the evidence on sex differences in colour liking more widely, the toddler work contributes the timing: no difference in infancy, a large and unstable one near the third birthday, and in Swiss samples almost no adult of either sex naming pink as a favourite. The laboratory evidence for adults is on the page for sex differences in colour preference.

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