Infradian Rhythms Flashcards
(7 cards)
What are Infradian Rhythms?
Infradian rhythms last longer than 24 hours and occur less frequently - menstrual cycle, which is around 28 days and is regulated by hormone levels such as oestrogen and progesterone. Another example is SAD, a yearly rhythm where reduced daylight in winter leads to depressive symptoms due to changes in melatonin and serotonin levels.
Stern and McClintock’s Menstrual Synchrony Study
investigated effects of pheromones on menstrual cycle synchronisation- collected pheromone samples from 29 women at diff stages of their cycle and applied them to other women. results showed that 68% women experienced changes to their cycle, bringing them to pheromone donor = cycle can sync due to pheromones
SAD
symptoms= persistent low moods, loss of interest, feeliing irritable
causes= reduced sunlight disrupting body’s natural rhythm, affect hormone production, and lower serotonin levels, contributing to feelings of depression
treatment= light therapy- use lightbox for 1 hr every morning during darker months. light mimics sunlight, reducing melatonin and increasing serotonin
weakness- low validity for evolutionary implications
Shank argues if too many women in a group shared the same cycle, it may lead to increased competition among men to have highest quality female = fewer men reproduce successfully, producing offspring that are less fit. this suggests it may not provide evolutionary advantage and challenges assumption that synchrony is adaptive = alt explanations should be explored
strength- Real-world application (SAD treatment)
Understanding infradian rhythms like SAD has led to effective treatments such as light therapy, which resets melatonin production and improves symptoms = knowledge of infradian rhythms can have practical benefits for those with seasonal mood disorders = therefore, research has real-world utility, improving quality of life for sufferers.
HOWEVER: the therapy doesn’t work for all individuals and may have a placebo effect, suggesting limitations in universal application.
weakness- Methodological issues in synchrony studies
Critics argue that studies like Stern and McClintock’s lack control over confounding variables- Factors such as diet, stress, and exercise can influence the menstrual cycle, and many synchrony studies rely on self-reported data = inaccurate. This questions the validity and reliability of findings that suggest menstrual synchrony is biologically driven = the evidence may not be as strong as initially thought.
weakness- SAD explanations may be reductionist
Although SAD is linked to changes in melatonin and serotonin, this explanation may be biologically reductionist.
It overlooks psychological and social factors, such as lifestyle, coping strategies, or cultural influences on mood. Therefore, a purely biological account may be too simplistic, limiting the overall explanation for infradian disorders like SAD.
