i think humans would find any way possible to manipulate this system for monetary reward. If someone could hack a computer a bit to emulate two humans to earn twice as much, then that system has a direct monetary reward.. and development shall begin.
Maybe it has to be proof of human with no computer hardware..
It just need to prove human activity - so something what it is hard to emulate or trick
some tests can be hidden from audience or be taken randomly during compilation, there is also a lot of possibilities and behavioural data to analyse.
https://bitcointalk.org/index.php?topic=1944481.0 Proof of Being HUMAN mixed with Proof of Work [ANN] [preICO] ICO Unicorns.WORLD
Obviously it need to be a inflation coin, but that is not a problem for currency as long as there is software build on it to boost popularity.