The European Marriage Pattern (EMP), in place in NW Europe for perhaps 500 years, substantially limited fertility. But how could such limitation persist when some individuals who deviated from the EMP norm had more children? If their children inherited their deviant behaviors, their descendants would quickly become the majority of later generations. This puzzle has two possible solutions. The first is that all those that deviated actually had lower net fertility over multiple generations. We show, however, no fertility penalty to future generations from higher initial fertility. Instead the EMP survived because even though the EMP persisted at the social level, children did not inherit their parents’ individual fertility choices. In the paper we show evidence consistent with lateral, as opposed to vertical, transmission of EMP fertility behaviors.