This one's seriously interesting.
Presence or absence of #play in adulthood among #primates is predicted by the politics! It's suppressed by 'despotic' systems:
'Adult play was not predicted by female body mass or sexual dimorphism, which are phylogenetically conserved. Social style was the key factor: tolerant species were more likely to exhibit the behaviour than despotic ones...'

https://royalsocietypublishing.org/rsbl/article/22/4/20250597/481535/Despotism-trumps-phylogeny-in-explaining