OBSAH
Překvapivé projevy hravosti u různých zvířat.
- Stuart BrownSelf - Play Researcher
- Mariana BrussoniSelf - Developmental Psychologist
- Gordon BurghardtSelf
- Matthew CooperSelf - Neuroscientist
- Ellen Beate Hansen SandseterSelf - Child Psychologist
- Kathy Hirsh-PasekSelf - Developmental Psychologist
- Kathryn KegelSelf - Seattle Aquarium
- Elisabetta PalagiSelf - Primate Researcher