The global life expectancy for 2020 is about 72 years. The global fertility rate is about 2-3 births per woman.
The strategies are made to ensure that the young offsprings could survive and develop into maturity.
It's the instinct that exist by all type of organisms. We had the drive to protect the younger generation who still hasn't developed yet, teach them
all necessary skill to survive until they could survive in their own. (such as when we teach our children how to read or when birds teach their offsprings to fly.<span />
