AO3

• A strength is that

  -knowledge of the circadian rhythms has given researchers a better understanding of the adverse consequences that can occur as a result in their disruption (desynchronization).
• Night workers engaged in shift work tend to experience...

  -periods of reduced concentration about 6am (a circadian trough) meaning mistakes and accidents are more likely to occur (Boivin et al. 1996).
• Knutsson found a relationship between shift work and...

  -poor health: shift workers are three times more likely to develop heart disease.

  -This may be in part be due to the stress of adjusting to different sleep/wake patterns and poor quality sleep during the day.
• A weakness is that (pop validity)

  -However, many studies into the sleep/wake cycle use small sample studies or case studies. These findings may not be generalizable to the population as a whole.
• Another weakness is that

  -that individual sleep/wake cycles can vary. Czeisler et al (1999), found that individuals varied from 13-65 hours.

  -Furthermore, Duffy et al (2001) revealed that some people display a natural preference for going to bed early and rising early (larks) opposed to people who prefer to go to bed late and rise late (owls).

  -individual differences
• Another weakness is that

  -Neuroscientists suggest that teenagers’ circadian rhythms typically begin 2 hours after those of adults.

  -In a pilot study at Monkseaton High School (2010), the school day started at 10am over a two year period. They found academic results improved and illness went down.
• A strength of circadian rhythms is that they

  -co-ordinate a number of the body’s basic processes

  -This can have an effect on the action of drugs on the body (pharmacokinetics).

  -Research into circadian rhythms has revealed that there are optimum times to take drugs which has led to the development of guidelines to do with drug dosing for a range of medications