Evaluation

• A strength is that there are supporting studies Such as Aschoff and Weber who studied participants who lived in a bunker that had only artificial light. They found that participants settled into longer sleep/wake cycle of between 25-27 hours. This shows that humans use natural light to regulate their 24hr circadian sleep-wake cycle, demonstrating the importance of light.
• A limitation is that there are individual differences and generalisations can be difficult to make. This is because the studies that are used have been based off small samples and the sleep-wake cycle can vary from person to person. This means that there may be innate individual difference in circadian rhythm which suggests that researchers should focus on these differences during an investigation
• a strength is that it can create medical treatments. circadian rhythms co-ordinate a number of the bodies basic processes such as heart rate and digestion. the rise and falls of these during the day has lead to doctors look at how medical treatment can be administered in a way that corresponds to biological rhythms. this means that there is real-life application into circadian rhythms and using them can bring benefits to society