Why should I help?  

If your child is between the ages of 12-16, we are seeking their involvement in an important study that will help us to understand more about how young people spend their free time. This will help us to identify which activities affect young people’s health and wellbeing.  

Will my child’s answers to these questionnaires be kept private?  

All data will be kept confidential. No personal information (name or identification number) will be recorded in this research and no information about individuals will be given to the schools that participate. All data will be processed anonymously. The results of this study might be presented online or in a scientific journal, but the data is not traceable to an individual.

What does participation involve?  

Children will be asked to fill out an online questionnaire every evening for a week in which they will answer questions about how they spent their leisure time during that day. This will take around 15 minutes to complete. Before the children start, we will ask them once a series of questions about other aspects of their lives such as their friendships, mood, and bullying. This will take about 30 minutes to complete.  

Your child’s participation in this survey is voluntary. If you agree to them participating in this study, you or your child can indicate at any time that you wish to withdraw, without having to give an explanation.  

How can I help?  

If your child’s school has been invited to participate in the research, a letter with a consent form will have been given to you by your child’s teacher, or you can download it here from the website. Depending on the age of you child, we may also need your consent for your child to take part in this study. Please refer to the consent form for more information.    

What if I have more questions?

If you need more information about the study, you could send an email to this address: This email address is being protected from spambots. You need JavaScript enabled to view it..      


Project lead: Prof. Carolien Rieffe This email address is being protected from spambots. You need JavaScript enabled to view it.  

Measuring children's behaviour at the playground

February 5th, 2020

Brenda playground

On the 31st of January, Brenda attended the Peer Relations Onderzoekers (PRO) meeting in Tilburg University. She presented preliminary results concerning the concordance of peers, teachers, and parents as informants about children's social competence, and the contribution that observation and sensor data might have to improve our views on children's behaviour at the playground. 


New PhD position in school inclusion project

February 4th, 2020


We are looking for a PhD student to join a unique multidisciplinary project defined within the Centre for BOLD Cities, entitled "Data-driven, urban policymaking for social inclusion of young, vulnerable people". It is a full-time position for 4 years. The PhD student has to be fluent in English and have strong programming skills. Click here to know more about the position and how to apply.


Naqi successfully defended his PhD dissertation

December 18th, 2019

Naqi Defense Dec2019 14Naqi Defense Dec2019 13

Today on December 18th, Naqi defended his PhD dissertation. Naqi's research focuses on the extent to which relationships between emotional experiences and aggressive behaviours in adolescents are affected by culture. He found that the traditional classification between individualistic Western countries and collectivistic Eastern countries was not fully supported when cultural values were assessed at individual levels, which may have important implications for future cross-cultural research and interventions. To know more about Naqi's research, click here for the university news article. 
Congratulations, Dr. Naqi!


What is fair? Fairness decisions in adolescents; the effect of hearing loss

November 15th, 2019

coins stacking

A sense of fairness is assumed to be innate, but is it? Adva examined fairness in deaf / hard-of-hearing (DHH) and hearing adolescents, presenting the participants with different situations to distribute coins between a peer and oneself. Although young DHH adolescents had more difficulties than their hearing peers to live up to the equity principle when it would cost their peer a coin, older DHH participants had more difficulties with equity when this implied less coins for themselves. The paper is available open access in Social Development. Click here to read it.

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Stories told by children and their Theory of Mind

November 13th, 2019

Max v Duijn 10Nov2019 2

On Monday November 10th, Max van Duijn, who received a NWO-Veni grant, visited our lab for a research meeting. Max presented the outline of his work examining the relation between children's Theory of Mind and storytelling. Click here to read more about his grant and project.


Recent & Upcoming Events

February 14th: Lecture at Durham University

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March 4th: Neeltje's defense & symposium

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March 13th: National Autism Congress

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One more week for Naqi's defense!

December 12th, 2019

Naqi Zijian Dec2019

Naqi came back to Leiden for his PhD defence next Wednesday 18 December, and took the opportunity to study factor analysis in R with our new PhD student Zijian. 


VNOP-CAS Research Days

November 26th, 2019


Shannon and Qi attended the VNOP-CAS Research Days on the 22nd of November in Utrecht. They presented their research plans and preliminary findings from their first-wave data collection in China, focusing on emotional functioning in Chinese deaf and hard-of-hearing toddlers.


Bachelor internship on inclusiveness at schoolyard

November 19th, 2019

Bachelor project schoolyard 2019

On November 18th, Lisa and Anna welcomed 10 enthusiastic bachelor students who will join our lab for an internship.

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Who are we?

FOE group 2019 crop

Our team is located at the department of Developmental Psychology of Leiden University in the Netherlands. We work in close collaboration with the Dutch Foundation for the Deaf and Hard of Hearing Child (NSDSK), the ENT department of the Leiden University Medical Centre (LUMC), the Centre for Autism, the Leiden Institute of Advanced Computer Science (LIACS), TU Delft, and University of Twente. Our group is dedicated to examining the emotional development of children and adolescents of all walks of life. We have a strong focus on the functionality of emotions, and its impact on children's social development. Besides typically developing children and adolescents, we are interested in the development of those who are deaf or hard-of-hearing, with autism spectrum disorders, or with specific language impairments.

On this site we regularly post news items about new publications, events, and so on. You can also read more about our ongoing projects, read about and download questionnaires we have developed,
see an overview of our publications per topic, or read about opportunities for students to join our team.