Thanks for the spot check! I had heard this number (~4 hours per day) as well and I now have much less confidence in it. That most of the cited studies focus on memorization / rote learning seriously limits their generality.
Anecdotally, I have observed soft limits for the amount of “good work” I can do per day. In particular, I can do good work for several hours in a day but—somewhat mysteriously—I find it more difficult to do even a couple hours of good work the next day. I say “mysteriously” because sometimes the lethargy manifests itself in odd ways but the end result is always less productivity. My folk theory-ish explanation is that I have some amount of “good work” resources that only gradually replenish, but I have no idea what the actual mechanism might be and my understanding is that ego depletion has not survived the replication crisis, so I’m not very confident in this.
Thanks for the spot check! I had heard this number (~4 hours per day) as well and I now have much less confidence in it. That most of the cited studies focus on memorization / rote learning seriously limits their generality.
Anecdotally, I have observed soft limits for the amount of “good work” I can do per day. In particular, I can do good work for several hours in a day but—somewhat mysteriously—I find it more difficult to do even a couple hours of good work the next day. I say “mysteriously” because sometimes the lethargy manifests itself in odd ways but the end result is always less productivity. My folk theory-ish explanation is that I have some amount of “good work” resources that only gradually replenish, but I have no idea what the actual mechanism might be and my understanding is that ego depletion has not survived the replication crisis, so I’m not very confident in this.