The effect of circadian rhythms on the anchoring effect in the legal context

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At a Glance


  • Context: -
  • Number of participants: 65
  • Number of days per participants: 3
  • Number of prompst per Day: 5
  • Number of Items: 4


The anchoring effect is a widely studied phenomenon and describes that when people have to make a decision they are disproportionately influenced by an initial presented value (Tversky & Kahneman, 1974). This is because anchors prime anchor consistent information. That is, information that helps determine whether the initially presented values (i.e., anchor) is a valid estimate. Information processing is thus biased in the direction of the anchor. Therefore increased information processing increases the anchoring effect.

The effect of circadian rhythms on the anchoring effect has not yet been studied. Circadian rhythms are known to affect a variety of cognitive functions such as memory efficiency. People with a morning chronotype tend to perform well early in the day, while people with an evening chronotype tend to show enhanced performance later in the day. Performing a task outside your optimal time (i.e., offpeak; e.g., an evening person performing a memory task in the morning) reduces memory efficiency and it could arguably decrease information processing as compared with performing a task inside your optimal time (i.e., on-peak; May, Hasher & Foong, 2005; Schmidt et al., 2007). In comparative anchoring tasks, the anchor serves as a semantic prime which activates information that is in line with the anchor. This activated information will be more accessible when making absolute decisions and may therefore have an influence on the absolute decision (Strack & Mussweiler, 1997). However, the activation of this information relies on memory which is known to be affected by chronotype. Hence, the information processing of the anchoring effect could be decreased when being off-peak, which should in turn reduce the anchoring effect. A similar effect has been found by Englich and Soder (2009); who demonstrated that reducing information processing by inducing positive mood, leads to a reduced anchoring effect. We are specifically interested in the effect of circadian rhythms on the anchoring effect in the legal context, since the anchoring effect could have a large impact on legal decision making. Due to the fact that today there are no studies examining the effect the circadian rhythm has on decision making influenced by anchors, our study aims to close that gap by comparing the performance at distinct times during the day.

To measure the circadian rhythm, participants will measure their body temperatures with thermometers four times a day starting 30 minutes after waking up. Body temperature will then be reported in degrees Celsius. Participants will receive a notification on their mobile phones reminding them to report their body temperature. They will measure their body temperature under their armpit and then report them back to us (online).