The Effect of Weekdays on Risk Tolerance

Thursday is consistently the most cautious day. Could it be that being progressively more tired as you go through the week and getting to Thursday, could that somehow express itself in terms of what kind of risks you're willing to take by Thursday? Or maybe some kind of mood effect takes over on Friday that overwhelms that fatigue. Another question I have is I wonder about interactions between risk aversion as expressed over different days of the week and our feeling of freedom about what we get to do each day of the week.