I am on page 43 of Kahneman’s book. He states there that high levels of concentration by what he calls System 2 of the brain causes ego depletion and actually drains a body’s physical resources (glucose). Some researchers studied eight Israeli parole judges. The judges processed cases all day with an average approval rate of 35%. Immediately after each food break there was a 65% approval rate. Right before the next food break the rate was zero.
I will be grading eighty final exams Tuesday and Wednesday. I intend to just sit down and get it done. It looks like I better be taking more frequent food breaks to be sure I grade the tests fairly.