@annaleen Seems as if that claim about the behavior of the majority of humans would require a lot of evidence not easily found. Yes, there are love letters by married people, romantic poetry and all the rest, but how would you ever really know/prove that most people were or weren't monogamous? The majority of people over time have no written history whatsoever. For those who were deemed important enough to record something, their sexual behavior may or may not be a matter of record.