A weaknes sof infradian rhythm?

-Methology used in synchronisation studies -Supposed parttern may have occured by chance, this may be why other stuides, such as Trevathan et al, have not be able to replicate the original findings by Stern and McClintock. -There are many factors that may change a woman's menstrual cycle and act as confounding variables (stress, changes in diet) -Suggests that menstrual synchrony studies are flawed