You're the one claiming there's a huge body of research disproving his claims. Your link upthread points to stuff that supports his argument and other stuff that counts as weak evidence against. Nowhere is there anything remotely like disproof. You can also find evidence (e.g. in http://cmdept.unl.edu/drb/Reading/overtime2.htm from the link above) that how you structure your work and rest periods can improve your production. After all, somebody doing office work 60 hours a week with some regular exercise is probably going to outperform somebody like me, who's fat and doesn't exercise. I certainly outperform myself on days that I walk to the office instead of driving. There's clearly some variance involved in individual employees' age, health, height, diet, and attitude, so it should be obvious that you can't just talk about averages over the construction industry and apply them to programming, and to all programmers, with the degree of certainty that you hold.