Evolutionary basis

• It may have been advantageous for our ancestors to menstruate together from an evolutionary point of view
• Women would fall pregnant at the same time meaning that new-borns could be cared for collectively within a social group increasing the chance of survival
• To counterargue, the validity of the evolutionary perspective has been questioned.
• Schank (2004) argues that if there were too many females cycling together within a social group, this would produce competition for the highest quality males, lowering the fitness of just any potential partner to produce offspring.
• From this point of view, the avoidance of synchrony would appear to be the most adaptive evolutionary strategy and therefore naturally selected.