Play is the removal of barriers. That’s why people get their feelings hurt when people joke and when we rough house.

Barriers exist to keep us from getting hurt.

Play allows the exploration of boundaries without consequence.

When play has consequences it is no longer play.
Jokes that deliberately hurt people’s feelings are not play.
Rough housing to cause deliberate injury is not play.

There is a fine line between play and not-play and the border is often crossed. It is at this boundary that injury can occur but without walking it occasionally in play how would anyone know where the boundary lies?

Essecially for those who grow up without boundaries or with poorly defined ones this is a critical aspect of socialization. Only by stepping over the line do they find out where that line lies. Doing it in play may cause harm but, if they are not entitrely anti-social, provides great learning.

The boundaries are different for everyone. When we first meet a person we have the complete set of boundaries raised between us and them. As we communicate with that person we learn what boundaries need to be kept when we’re around them and which don’t.

The more we trust the other person will not hurt us the lower the boundaries become.