5 Questions with Dr. Sergio Pellis

Dr. Sergio M. Pellis has been a professor at the University of Lethbridge since 1990 with the main focus of his research being on the role peer-to-peer play has in the development of social competence. Using various species, ranging from laboratory rodents to primates, such as the great apes, Pellis has shown that rough-and-tumble play is composed of dissociable subcomponents (e.g., attack, defense) and that there are species differences in how such play can be modified at different ages and contexts.

What first piqued your interest in your research discipline?

It came in several steps. The first, when I was five years old and realized that my ambition in life was to study animals; the second, midway through my undergraduate degree in zoology when I realized that the behaviour of animals was what turned me on the most; the third, by the end of my degree when I realized that the most intriguing aspect of animal behaviour was how it develops; and the fourth step was when I discovered that play, a feature of behaviour common to the childhood of many animals, posed an intriguing problem concerning development. The last step came when I was doing post-doctoral research in behavioural neuroscience and realized that looking at the brain was another important avenue by which to understand behaviour and how it changes over time. Altogether, this led to an interest in how the brain produces and regulates play behaviour and how play behaviour changes the functioning of the brain.

Sergio Pellis
Dr. Sergio Pellis believes unstructured play has a major role in child development.

How is your research applicable in "the real world"?

Aside from providing a model for further research into understanding the mechanisms that underlie the feedback relationship between brain and behaviour, the "real world" applicability of my research concerns our societal practices in child rearing. The current trend for both parents and schools to curtail the opportunity for free play in general, and rough and tumble play in particular, may have important implications for the development of social skills in children. Indeed, there is data, albeit given the limits imposed on research on humans, that show that children with greater opportunity to engage in free play, especially rough housing play, are socially more proficient and score better in their academic work. Our laboratory-based experiments on rats provide evidence for the causal mechanisms by which play may have these beneficial effects.

What is the greatest honour you have received in your career?

To have been able to work on the problem that has been of most interest to me, to have made some novel discoveries and to have peers use some of my work as a basis for developing and testing hypotheses. Even more exciting has been independent support for some of the ideas generated in my laboratory. That is about as good as it gets.

How important are students to your research endeavours?

Undergraduate and graduate students, as well as post-doctoral fellows, have been an instrumental part of my research program and the successes that I have had in that program. Students bring several assets to a research program. First, they are young and full of energy. Second, they are motivated to succeed. Third, they bring fresh eyes and insights to the problem under investigation. The best students that I have had are those who have challenged what I told them is important or noticed something new in the phenomenon that I had missed. I have found that directing a good student to a problem, giving them ownership of that problem, and letting them loose on it, has, many times, produced major breakthroughs in the research. I wouldn't have reached the level of understanding about play that I have without the valuable contributions of the students who have worked with me.

If you had unlimited funds, which areas of research would you invest?

As well as unlimited funds, this scenario would require multiple lifetimes, but if you are going to dream, dream big. I would still study play, but I would push the two lines of research that I study now to greater depth.

First, I would combine levels of analysis – behaviour, brain anatomy at the cellular and sub-cellular level, genetic and other molecular changes associated with play, and electrophysiology of specific brain areas known to be associated with play. Such an integrated approach would allow a full mapping of the brain changing effects of play experience in the juvenile period, and characterize how those changes transform the functional capabilities of the brain.

Second, one of the insights that has arisen from my work on the play of rats and other rodents is the finding that the ability to 'play with play' depends on specialized mechanisms in the cortex, particularly the prefrontal cortex. It is likely that changes in these mechanisms have led to the evolution of the human exaggeration of fantasy in their play.

I would like to finally answer the question of how humans have evolved their seemingly unique features of play, and so would be able to characterize the brain changes that are involved in producing those features.

Each month, the Legend will present 5 Questions With . . . one of our researchers. For a look at the entire catalog of 5 Questions With . . . features, check out the Office of Research and Innovation Services website at If you'd like to be profiled, contact Penny Pickles at

This story first appeared in the February 2013 edition of the Legend. For a look at the full issue in a flipbook format, follow this link.