5. It was proposed in one study that the normal, unremarkable experiences associated with everyday living can deplete one’s capacity to resist moral temptations (Kouchaki, et al. 2013).
The study proposes that people are more likely to have less self-control when they’re tired. Another study concluded that the average adult has less self-control as the work day wears on, becoming more likely to act “immoral” by the end of the afternoon (Barnes, et al. 2014). It could be tied to the study by the Florida State University that restoring glucose to a sufficient level typically improves self-control. And it turns out that in 2009, the Stanford University School of Medicine found that circadian rhythms are directly tied to the mechanism that processes blood sugar.
This works both ways, the studies above have mentioned that people tend to engage in immoral behaviour when they’re tired due to the lack of self-control. However, the lack of self-control can also cause people to let their guard down a little bit and be more honest with physical conditions.