Editing Concealed ovulation (section)

===Cuckoldry hypothesis===

Schröder in his review writes that Benshoof and Thornhill hypothesized that estrus became hidden after monogamous relationships became the norm in ''[[Homo erectus]]''.<ref name="Schroder 1993" />  Concealed ovulation allowed the woman to mate secretly at times with an alternative man, and thus gain the benefit of his genes for her offspring, while still retaining the benefits of the pair bond with her usual sexual partner.  Her usual sexual partner would have little reason to doubt her fidelity, because of the concealed ovulation, and would have high, albeit unfounded, paternity confidence in her offspring.  His confidence would encourage him to invest his time and energy in assisting her to care for the child, even though it was not his own.  Again, the idea of a man's investment being vital to the child's survival is a central fixture of a hypothesis regarding concealed ovulation, even as the evolutionary benefits accrue to the child, the woman, and her clandestine partner, and not to her regular sexual partner.