Heartiste reports that monotheistic religions may encourage paternal certainty. Patriarchal societies, more generally, probably require a high level of paternal certainty. Most societies throughout history have been patriarchal, so it's no surprise that cuckoldry rates among Europeans over time appear to have hung around in the 1%-2% range. In matriarchal societies, paternal certainty rates are presumably lower.
Monogamy, of course, guarantees paternal certainty. In encouraging--and to a large extent, normalizing--monogamy, monotheistic religions also encourage paternal investment. Paternal investment, in turn, is a prerequisite for advanced civilization (see sub-Saharan Africa, Haiti, or Detroit).
There is the question of causation to consider, too. Did monogamy and paternal certainty shape societal evolution or did evolution shape social norms vis-a-vis monogamy and paternal certainty? It's probably a combination of the two through the process of gene-culture coevolution, but I'm not qualified to comment on that with any certainty of my own.
CH is on record (check the archives) predicting that the wholesale abandonment of religion by Western societies will lead to higher rates of cheating and cuckoldry, by both men and women.The data to test that assertion exist. The percentage of married white men who have cheated on their wives by frequency of religious service attendance (for contemporary relevance all responses are from 2000 onward and attendance categories are exclusive, combined n = 9,205):
|Yearly at most||22.0%|
|Monthly at most||19.1%|
|More than monthly||16.0%|
|At least weekly||15.5%|
The same for married white women who have cheated:
|Yearly at most||18.6%|
|Monthly at most||12.3%|
|More than monthly||9.2%|
|At least weekly||8.6%|
Those actively involved in monotheistic religions are less likely to philander than those who are not.
Couple that with the decline in both church attendance and religious affiliation and it seems that the conditions for increasing cuckoldry are indeed present. Heartiste nailed it.
GSS variables used: EVSTRAY(1-2), SEX, YEAR(2000-2014), RACECEN1(1), ATTEND(0)(1-2)(3-4)(5-6)(7-8)