i&#x27;m too lazy to read all the papers on this subject, so indulge me: Do any measure brain &quot;output&quot;?<p>i bet earlier humans would eat a lot, then walk for miles until finding another spot, or stuff them on seals and then sleep on some warm cave and do nothing until the hunger was bad enough to justify another hunt on the cold outside, etc. I doubt you can live that way with a 9-5 job.