This is what he termed as the “grandmother hypothesis”; which is meant to ensure survival of existing lineage.
Based on the idea that women would invest more time in family, and the existing hypothesis that married women have a later age on natural menopause than unmarried women.
scientists at the University College London observed that women who engage in sexual activity weekly or monthly have a reduced risk of premature menopause compares to those who had some form of sexual activity less than monthly.
Who would have thought that women who are more sexually active would retain fertility for much longer than women who have sex less frequently? Basically, what this means is that women have to use it or lose it!