Very interesting. But I'm not convinced this has anything to do with washing specifically. I suspect it might just be that performing an ordinary, rote activity interrupts the normal process of the decision making activity and the feeling of completion carries over back into the other activity. I wonder if tasks such as tying one's shoes, packing a box and sealing it, etc. would have a similar effect.<p>Ultimately the study doesn't provide enough data to fully support the hypothesis (that cleansing, washing away provides some mental, decision making benefit), though the fact that there's any effect at all warrants a lot of further study.