“Lack of playing leads to maladjusted behaviour.”

“Just because it's fun.” That is the answer you can expect when you ask a child why they are playing. Playing is also an extensive phenomenon in the animal kingdom. Rats play, dogs play, there are bird and reptile species that play. Something that occurs so often surely MUST have a function that goes beyond ‘because it's fun.’ What that exact function is is being investigated by neurobiologists Professor Dr Louk Vanderschuren and Dr Heidi Lesscher, who both have ties to the Faculty of Veterinary Medicine.

Natural rewarder

The fact that playing is so fun indicates that it is a natural rewarder; a behaviour that contributes to the survival of the species, like sex and eating. The theory behind this is that our brains have evolved in such a way that we find those behaviours pleasant to do. Without reproduction, the species will go extinct. And without food, you will not survive. And what are the effects of not playing? 

Lesscher and Vanderschuren investigate playing by looking at what is happening when animals play and also what they do if they are denied the possibility to play. They seek answers to question such as: What happens in the brain during playing? Which mechanisms ensure that an animal achieves the ‘correct’ amount of playing? How do animals understand that something is playing? What makes playing contribute to developments in the brain?

The consequences of not playing

Vanderschuren and Lesscher have already shown with their research that playing contributes to those developments: young rats who have not been able to play experience difficulties with complex situations and interactions later in life. Vanderschuren says: “These animals can handle simple tasks and situations, but we see a clear difference in both cognition and behaviour as soon as something unexpected happens.” For instance, one of the experiments is the 5-choice serial reaction time task. For this task, a rat has to respond to a light that appears in one of five possible locations. If the animal does that correctly, it will receive a reward. Rats who did not play in a crucial phase can still learn this task. But if something unexpected occurs in the rules of the task, such as having to wait a little longer for the light, those rats have far more trouble dealing with that. Rats who did learn to play recognise the new situation and adjust their behaviour to it.

Lesscher says: “We also see the consequences of deprivation of playing in interactions with others of the same species. An animal that has been able to play sufficiently will use the threat of aggression to achieve a goal, such as making an intruder go away. An animal that could not play will show maladjusted behaviour and will resort to violence faster. It lacks the flexibility and resilience to handle complicated situations properly.”

Healthy play, better coping

Like with young animals, playing is also essential to children for a healthy development. But it is unfortunately not a given that all children can play, such as the 600,000 children in the Netherlands who have chronic illnesses. An insufficient amount of playing can eventually result in negative consequences for these children. In order to handle that problem, Vanderschuren and Lesscher collaborate with other researchers and societal organisations in the multidisciplinary research project 'Healthy play, better coping', which is a part of the research theme Dynamics of Youth of Utrecht University. Lesscher says: “Every partner contributes from a unique angle and expertise, and that is very enriching to all of us. For instance, research by the Wilhelmina Children's Hospital shows that belonging and being able to participate are very important to ill children. That gives us new ideas for our fundamental research.”

From lab to climbing frame

Lesscher and Vanderschuren also collaborate with colleagues who develop games that enable ill children to participate and belong after all. One of the partners outside the university is Jantje Beton, an organisation dedicated to providing more accommodations and time for children to play. Pauline van der Loo of Jantje Beton explains: “It's quite a challenge to show the impact of our work on society. That is why the scientific foundation of the importance of playing is very valuable to Jantje Beton. In return, we then contribute expertise on how to have conversations with children on playing and on what's important to them.” One of the following steps in the project is the development of a measuring instrument that makes playing by children better to measure and characterise.

"As a society, you can ask yourself the question: Does a bump on your head outweigh all the benefits of playing?”

Exploring boundaries

Playing is a way for children to seek out boundaries and move them, both physically and in social situations. Lesscher says: “Game therapists of the HU University of Applied Sciences Utrecht whom we collaborate with see that children often go just a bit higher than they can actually handle while playing, such as on a climbing frame. That lets them find out what they can do and what they can't do yet. AND that by practising and experimenting, they can eventually achieve their goal after all.”

But will that not result in accidents? “No, quite the opposite. Norwegian research shows that risky behaviour during playing makes children very aware of what they're doing. The number of accidents that require First Aid also turns out to be lower among children who play in risky ways.” So climbing frames should be towering? Vanderschuren says: “You should of course consider safety very well. But you can ask yourself as a society: Does a bump on your head outweigh all the benefits that playing has for very many children? The more we know about playing based on our fundamental research, how it works and its function is, the more we can contribute to a healthy environment in which children can develop themselves as well as possible.”

This is an article from Vetscience Nr. 5, July 2019