The 40 hour work week is a sweeping kind of a claim you wouldn't accept in any other context. It's like saying that to maximize the benefits of physical exercise, you shouldn't work out more than 10 hours a week, then proceeding to ignore the type of benefit you're looking for, anatomy, intensity, intervals, session length, fun, safety, individual talent etc.
I've seen frequent claims on LW that shorter hours are better for productivity, but very little data to back them up. Why don't people quote some studies so that we can scrutinize them to see if they actually say what people claim they say?
As a side note, what do you people do on your free time? Unless you're letting your brain idly daydream much of what you do on your free time could be considered hard work by others.
As a side note, what do you people do on your free time?
Off the top of my head, in very roughly decreasing order, sleeping, browsing the web, hanging out with friends at the pub, playing the bass, listening to music, having sex, studying languages, eating, cooking, going shopping, reading books, watching movies, sightseeing.
Unless you're letting your brain idly daydream much of what you do on your free time could be considered hard work by others.
Many of the things in my previous paragraph have very few people doing them for a living. And there are reasons for that.
Conventional wisdom, and many studies, hold that 40 hours of work per week are the optimum before exhaustion starts dragging your productivity down too much to be worth it. I read elsewhere that the optimum is even lower for creative work, namely 35 hours per week, though the sources I found don't all seem to agree.
In contrast, many tech companies in silicon valley demand (or 'encourage', which is the same thing in practice) much higher work times. 70 or 80 hours per week are sometimes treated as normal.
How can this be?
Are these companies simply wrong and are actually hurting themselves by overextending their human resources? Or does the 40-hour week have exceptions?
How high is the variance in how much time people can work? If only outliers are hired by such companies, that would explain the discrepancy. Another possibility is that this 40 hour limit simply does not apply if you are really into your work and 'in the flow'. However, as far as I understand it, the problem is a question of concentration, not motivation, so that doesn't make sense.
There are many articles on the internet arguing for both sides, but I find it hard to find ones that actually address these questions instead of just parroting the same generalized responses every time: Proponents of the 40 hour week cite studies that do not consider special cases, only averages (at least as far as I could find). Proponents of the 80 hour week claim that low work weeks are only for wage slaves without motivation, which reeks of bias and completely ignores that one's own subjective estimate of one's performance is not necessarily representative of one's actual performance.
Do you know of any studies that address these issues?