A03

• Point: A strength of research into circadian rhythms is that it gives us insight into the effects of desynchronisation.

  Evidence: For example, Boivin (1996) has shown that night working experience reduced concentration around 6AM, making mistakes and accidents more likely to happen.

  Explain: Similarly, further evidence revealed that shift workers are three times more likely to develop heart disease than those who work typical work patterns.

  Link: Therefore, such findings can have real-world economic implications as employers have to consider how best to manage worker productivity.
• Point: However, a limitation is that most studies exploring the effects of shift work tend to use correlational methods.

  Evidence: Such evidence makes it hard to establish whether the desynchronisation of the circadian rhythm has actually caused the negative effects.

  Explain: This is highlighted by Solomon (1993) that shows that high divorce rates in shift workers might be due to other influences such as missing out on important family events.

  Link: Therefore, this suggests that it may not be biological factors that cause the negative consequences associated with shift work.
• Another strength of research into circadian rhythms is that it has been used to improve medical treatments.

  e.g, research has shown us that circadian rhythms co-ordinate a lot of the body’s basic processes, such as heart rate, digestion and hormone levels.

  This is important in chronotherapeutics, which is how medical treatments can be administered in a way to best match a person’s biological rhythms, such as taking aspirin at night to treat heart attacks.

  Therefore, this shows how circadian rhythm research has helped increase the effectiveness of drug treatments
• A limitation of research into circadian rhythms is that it is difficult to make generalisations.

  For example, Siffre’s study consisted of only himself as the sample and research has shown that there are major individual differences in sleep/wake cycles (between 13 to 65 hours).

  These differences aren’t just between individuals, but also vary with a person as they age, as Siffre observed his own sleep/wake cycle slowed down as he got older.

  Therefore, it is difficult to make meaningful generalisations regarding sleep/wake cycles based on the research that was done.