The authors of a recent paper estimated that up to 60% of men and 50% of women report extra-marital partnerships in their lifetime - and they believe those numbers are under-reported, especially among women, due to cultural constraints. In reality, range estimates are so broad as to be almost meaningless but even if it's 20% it's a lot.
Because it's Africa, estimates become even fuzzier. Presumably, extramarital affairs in America would involve condoms or at least a note from a doctor to proceed - not so everywhere, and thus HIV is a bigger concern and a stigma when it comes to honesty about behavior. And then general polygamy in some cultures skews results and also just rampant sex.
Regardless of the specifics, fishermen and truck drivers are apparently still getting busy there just like they did here 40 years ago.
The authors used 1090 gender-matched interviews (545 couples) and 12 focus group discussions with 59 couples. 6.2% of women reported an extra-marital affair in the last six months.
What reasons did they list?
Denial of a preferred sex positions, a longer penis, younger age and increased sexual satisfaction topped the list and, of course, domestic violence. In other words, the same as every woman who has ever had an affair.
CLICK IMAGE FOR FULL SIZE. Partial table of relationship and sexual attributes by extra-marital partnership status among women married to fishermen along Lake Victoria in Kisumu County.
Citation: Kwena Z, Mwanzo I, Shisanya C, Camlin C, Turan J, et al. (2014) Predictors of Extra-Marital Partnerships among Women Married to Fishermen along Lake Victoria in Kisumu County, Kenya. PLoS ONE 9(4): e95298. doi:10.1371/journal.pone.0095298