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First Friends Study

About the First Friends Study

First Friends Study

This study is part of a long-term programme of work on early development that Professor Hay has conducted in London, Cambridge, Canada, and the United States. We have studied one- and two-year-old children with their brothers and sisters, and their friends, and have found that toddlers are well able to relate to other children. Some of our findings have been surprising; for example, in a study of London toddlers, we found that one- and two-year-olds were more likely to share toys with their friends than to try to grab toys away from other children!

Although there are inevitably some quarrels between young children, these are surprisingly uncommon and often resolved very rapidly by the children themselves. Grabbing toys is very rare, and hitting even rarer. And, another surprise: in 20 years of studies with one- and two-year-olds, we have found very few differences between girls and boys.

In the First Friends study, we extended our research to an even younger age. We believed it was important to study children’s abilities to make friends from the very beginning, when babies are first meeting other babies informally, long before they are enrolled in playgroups or nursery classes. We asked parents of 9- to 15-month-old children to come to the School of Psychology with a friend who had a baby of similar age. We filmed the infants’ play for 25 minutes.

We discovered that the ability to play with other children emerges in the last months of the first year of life—when children first begin to crawl, show interest in particular toys, and start to understand how the world works. We also noticed that the infants hardly took their eyes off their friends, spending more time watching each other than looking at their parents or their friends’ parents.

Once again, we found very few differences between girls and boys. However, we were surprised to learn that the babies got along slightly less well when they were dealing with friends of the opposite sex! They were more likely to resist the other babies’ attempts to touch them or touch their toys if they were playing with a friend of the opposite sex. However, all the infants were more likely to show or give toys to their friends than to snatch toys away, and, as in our previous studies, there was almost no hitting or kicking. These very young infants were clearly interested in and played nicely with their familiar peers.


A PhD student in our research group, Rhiannon Fyfield, has used the videos from the First Friends Study to examine the extent to which young infants use repetitive behaviour, which in older individuals is a diagnostic sign for autism spectrum disorder.  It turns out that all infants in this age range characteristically show repetitive motor actions like flapping their hands or repetitive actions on physical objects like banging toys.  Thus repetitive behaviour at this age has positive functions for development and is not a sign of developmental delay or disorder.  These findings have been presented at conferences and will be included in Rhiannon Fyfield’s doctoral thesis.
We have presented our findings from the First Friends Study in conferences in the UK, Germany, the Netherlands and the USA.  We have also published the findings in developmental journals:


Information for Parents

Hay, D.F., Hurst, S.L., Waters, C.S., & Chadwick, A.  (2011). The developmental origins of intentional instrumental aggression.  Infancy, 16, 471-489.

Hay, D.F., Nash, A., Caplan, M., Ishikawa, F., & Vespo, J.E. ( 2011). The emergence of gender differences in physical aggression in the context of conflict between young peers.  British Journal of Developmental Psychology, 29, 158-175.