Infradian Rhythms.

Infradian Rhythms are longer than 24 hours, for example, hibernation and the human menstruation cycle.

Research.

McClintock's menstrual synchrony studies (1971)

M identified the synchronisation of cycles after observing menstrual cycles had synced through pheromones secreted and transmitted through social interaction.

Procedure:

- Longitudinal study with 29 women with a history of irregular ovulation.

-  Gathered samples of pheromones at different points in cycle by placing cotton wool under arms for 8 hours.

- Each cotton pad was then…