Each human organism is born with karmic dispositions, characteristic ways of acting.
Then it receives social input, Garbage In, Garbage Out.
Thus, karma + GIGO = a person.
Serene reflection meditation unravels GIGO and addresses karma.
However, organisms die before the issues are resolved.
Organisms were not designed but evolved.
Therefore, no designer is responsible.
I think that karma is genetic, not reborn.