Repeating surveys to track development over time

It’s been 6 months since we launched Baby Loves Science, and released our first survey - the Early Humour Survey. Now we’re repeating it! You might wonder why, so I thought I’d use this blog to explain. If you missed out our original blog on early humour development, you can check it out here.

One big reason to re-run the survey is that we need more people. In order to validate a new survey you need to run fun statistics like factor analysis, which tells you if your survey is any good or not. For the maths to work out, you need at minimum 100 participants (though there is lots of disagreement about the exact number of participants- some suggest 200, 300, or more!) Then it’s best to have at least another 100 participants to replicate the finding and make sure you didn’t find your results by chance. While the recently developed Early Motor Questionnaire, which looks at how babies’ motor skills develop over time, had around 100 participants, several recently developed parents surveys have way more participants than this. For instance, the Baby Care Questionnaire, which looks at parenting styles, had over 600 participants! Over 60 parents completed the Early Humour Survey last time (yay! and thanks!), but that means we need at least another 140 new people - or 540 new people according to some statisticians!

Another important thing that developmental psychologists want to know is, of course, how kids develop. One way to look at this is to see what different kids do at different ages. So, for instance, on average 18-month-olds might not be interested in humour involving silly words like “oogy boo”, but 24-month-olds might. If this is the case, this would show that as children age and have more experience with language and social encounters, and as their brains develop, they might appreciate and produce new types of humour.

However, even better than looking at different kids at different ages is to find out what the same kids are doing at different ages. This takes out some of the randomness of having different groups of children at different ages. For instance, imagine that, by chance, we got a sample of 24-month-olds who mostly like jokes involving silly words, and a sample of 18-month-olds who didn’t, and that this didn’t have anything to do with age. Maybe those were just personal preferences. By testing the same kids at different ages, we can eliminate these types of random effects. If our 18-month-olds who didn’t like jokes about silly words do like them 6 months later, we know that this has to do with development, and not just this group of kids.

Another reason to test the same kids at different time points is to look at how stable children’s humour is over time. Some kids just might be more into humour than others. Or some kids might really like verbal humour, but not physical humour, while other kids might have the opposite preference. By having parents complete the survey at different time points, we can see if kids’ humour and humour preferences are stable over time or not. This could give us insight into whether, for instance, different kids have different humour styles.

You can participate in the Early Humour Survey this month if you have a child between 0 and 47 months - whether you completed it the first time or not. We want to hear from you whether or not your child laughs or understands jokes yet, whatever country you are from, and whatever your child's type of development (e.g., premature, ADHD). Just register or sign into

Dr Elena Hoicka is a Lecturer (equivalent to Assistant Professor) in developmental psychology at the University of Sheffield, in England. Her research focuses on the early development of humour, pretending, deception, and learning.


Libertus, K., & Landa, R. J. (2013). The Early Motor Questionnaire (EMQ): A parental report measure of early motor development. Infant Behavior and Development, 36(4), 833-842.

MacCallum, R. C., Widaman, K. F., Zhang, S., & Hong, S. (1999). Sample size in factor analysis. Psychological Methods, 4(1), 84.

Winstanley, A., & Gattis, M. (2013). The Baby Care Questionnaire: A measure of parenting principles and practices during infancy. Infant Behavior and Development, 36(4), 762-775.