Hardly surprising. When childhood mortality is high people grow up seeing their siblings and friends die as a common thing, and understand it could just as easily be them. With low expectation of survival, life is less intrinsically valuable and risk avoidance is not critical. Change things around such that everyone has a very good chance of living a long, healthy, prosperous life so long as they don't fuck it up, and risk aversion skyrockets. It's easy to forget that the generation currently in power in most industrialized nations is the first in human history to be raised thinking survival to adulthood was a given.