It was found that for all ages males were willing to accept females that are slightly older than they are on average 4. A theory that can explain this finding from an evolutionary perspective is the parasite-stress theory which explains that an increase of infectious disease can cause humans to evolve selectively according to these pressures. The little shepherd of Kingdom Come. As access to education increases worldwide, the age of marriage increases with it, with more of the youth staying in education for longer. In modern times, this rule has been criticised as being more accurate for men than women, and for allowing a greater maximum age for a woman's partner later in her life than is actually socially acceptable. Biological Sciences,—
Evidence also shows that as disease risk gets higher, it puts a level of stress on mating selection and increases the use of polygamy.
Dating and the age gap: When is older too old?
What's the acceptable age difference in a relationship? Polygynists and their wives in sub-Saharan Africa: It has been found that married women are less likely to be partnered with a younger male compared to non-married women  in comparison to more recent findings, which provides evidence to suggest that previously married women are more likely to engage in an age-hypogamous sexual relationship compared to women who are married or who have never been married. A study suggested that age disparity in marriage is positively correlated with decreased longevity, particularly for women, though married individuals still have longer lifespans than singles. Comparatively in Western societies such as the US and Europe, there is a trend of smaller age-gaps between spouses, reaching its peak average in Southern Europe of 3.