> One of the psych principles I used to lecture about often in my keynotes was on boundaries as freeing, and discussed an experiment where children clustered ar

> One of the psych principles I used to lecture about often in my keynotes was on boundaries as freeing, and discussed an experiment where children clustered around the sandbox in a playground with no fence, but used the entire playground area when there was a fence. In both cases there is a boundary condition and distribution is biased towards the boundary. (Sand/Grass transition is a boundary). So the fence is not 'freeing' anything: it is simply demarcating the [extended] 'space of play', and is a stronger boundary condition (physical fence) than the material boundary (sand/grass).