circadian rhythms Flashcards
strength: Research by Siffre has demonstrated the ways in which the sleep/wake cycle is a circadian rhythm
E – Siffre (1962) spent two months deep underground in the caves of the Southern Alps, with nothing apart from a small lamp. During this time, he found his sleep/wake cycle increased slightly, to around 25 hours.
E – Siffre’s research demonstrates that the sleep/wake cycle is a circadian rhythm as it is free-running. Although Siffre’s sleep/wake cycle did change a bit, it still maintained a rhythm close to 24 hours. This suggests it is free-running, meaning it can maintain a roughly 24-hour rhythm without the presence of external cues (like daylight).Another issue to be aware of is that this study was only on a single person, and this may mean generalising to everyone’s circadian rhythms may be difficult.
L – Therefore, this research supports the claim that the sleep/wake cycle is a circadian rhythm, as it demonstrates the cycle is free-running and entrainable, although the limitations of the study may undermine this claim.
strength:Research into circadian rhythms has important implications for health.
E – Research into the effect of shift-work (where workers are required to work some night shifts) on health has found that shift workers are three times more likely to develop heart disease than workers who do not have to do shift work.
E – This shows how the disruption of our natural circadian rhythms – which occurs when a worker has to stay awake at night, when their free-running rhythm would encourage them to sleep – can be damaging to health. This has economic implications, as the health costs of shift-work will result in people becoming unwell, requiring expensive medical attention and/or being unabelt o work, rendering them economically inactive.
L – Therefore, this demonstrates the importance of research into circadian rhythms.
limitation: Researchers have found individual differences in the timing of circadian rhythms.
E – For example, Duffy et al. (2001) found that ‘morning people’ prefer to rise and go to bed early (about 6 am and 10 pm) whereas ‘evening people’ prefer to wake and go to bed later (about 10 am and 1 am).
E – Understanding how the timing of circadian rhythms vary for individuals could benefit society by, for example, allowing organisations to tailor work schedules to suit an employee’s individual circadian rhythm, thereby maximizing that person’s productivity. This means that research into the individual differences of circadian rhythms has economic implications, as it could help workers be more productive.
