Alright, I'll be that guy. I have no trouble doing more than 4 hours worth of mentally strenuous work in a day, and neither do most of the people I work with. Frequently enough I've put in sustained 12-16 hour days for weeks on end to meet a tough deadline.
You'll generally find that the most successful people who are best at what they do have no trouble with this either. I'll go further and say that a large number of the people who complain about having to work more than a few hours a day are doing nothing more than rationalizing their lazy HN and/or reddit habits.
Proving theorems is a completely different class of work to chipping away at your failed unit tests or knocking together a CRUD app in your favourite language. Maybe a tenth of one percent of software developers routinely do work that is intellectually on a par with mathematical research; The rest are for the most part skilled tradesmen, doing work they understand relatively well.
It is universally accepted that all but the most prodigious musicians do not benefit from more than 4 or 5 hours of practice a day. They can often easily do twelve or sixteen hours a day, but the extra time is simply wasted. Once your reserves of concentration are spent, you're just going through the motions without learning anything. Most conservatories go to great lengths to persuade their students to practice less, because young musicians are often convinced that they can attain mastery through sheer force of effort.
I can sit and transcribe or arrange parts all day long. I can play from sheet music until my hands give out, all the while daydreaming about what I'm having for tea or what chores need doing. I can't usefully improvise or compose for more than about two hours at a time, or more than four hours in a day. I can feel the point at which I start playing familiar riffs rather than truly improvising; When I've run out of ideas and I'm just writing pastiche. There are composers who claim to do regular eight-hour days, but when you look deeper they invariably spend most of that day arranging or transcribing or recording into the computer, stuff that's essentially just admin.
I might agree with that in an absolute sense. But if we're going to talk about percentiles, and relative to the human population, very few people (percentage-wise) can even do the "easy, boring" part of programming you're referring to.
Just recently I was given a task of debugging a major problem with our website that was causing frequent emergencies -- and apparently, was mystifying the developers.
My lead realized I'd need to understand the website's infrastructure first, so he took about 45 minutes explaining how it all fit together and where the problem occurred. But once I got to that point, my reaction was, "Wait -- wouldn't the problem go away if you just ... didn't do $STEP at that point?"
Turned out to be the entire solution to the problem.
I find that I can focus intensely for shorter bursts over a couple hours, but then I hit my limit and need to push the really hard stuff aside for a while. Sure, I can crank through a ton of tedious or menial tasks (and there are certainly plenty of them), but that's really not the same.
When I complain about being expected to sit around for 8, 9, 10 hours a day (and I do occasionally complain), it's not because I'm rationalizing lazy habits or want to get out of work. I love my work.
No -- It's because in only 3-4 of those hours I will finish 90% of what I ultimately get done in a day. The trick is in knowing how to optimize those hours of productivity, and when to go home and give your brain time to decompress.
It's been shown what actually happens in such a scenario is that your judgment quickly becomes impaired to the point where you are no longer capable of judging how impaired you are; it's the equivalent of being permanently drunk. To be sure, you can still press keys. If the work you're given is far enough below your peak ability, you may even eventually blunder your way into a solution. (Or you may not; last I checked, the failure rate of software projects is still several tens of percent, and stupid hours feature prominently in most of the failures.) But the calendar time to get your job done is longer, not shorter, than it would have been with an intelligent schedule. Degrading yourself like that is nothing to be proud of, and it does nothing but harm to your work as well as yourself.
People say that like I'm supposed to be impressed, but they don't seem to realize that programmers can be negatively productive. In 10 minutes of stupid, I can put in a bug that soaks up a day of somebody's time later on. But the people proud of their death marches act as if the bugs are all caused by cosmic rays, not their own previous exhausted fumblings, miscommunications, typos, and oversights.
In 17 years of managing many dozen staff, mostly developers admittedly, in a variety of different settings, I've never seen a someone that managed to be productive with mentally strenuous even a full 8 hour day at a time other than very occasionally when they're on a roll. Generally, the ones that do best are those who manage to spread out their work, take proper breaks and intersperse the rest of their mentally demanding work with "menial" tasks, and who goes home and puts their work away completely.
Maybe your're an exception, but if you are, be prepared that people will either disbelieve you or expect you to prove it. More likely, your idea of "sustained 12-16 hour days" only actually involves a few hours of what the rest of us would consider mentally strenuous work a day.
Put in 12-16 hour days for a while with repetitive, simple tasks taking most of the time when working on something that is overall exciting, sure, that works for a while (though eventually that too tends to produce burnout - I've had to order developers home after the strain starter producing negative results with fewer hours than that).
For me, what works best is that whenever I feel that my concentration is slipping, if I don't feel I have time for a proper break, I will switch to mindless tasks, such as updating my todo list (often spending time breaking bigger tasks into tasks that are realistically small enough for windows of a couple of hours), doing my e-mail, or if I'm home I'll do the housework, and I'll try to "switch off" while I do, practicing mindfulness meditation for the truly "mindless" tasks such as cleaning.
Sometimes I get lucky, and my concentration stays on top for longer in one go, and I cherish those moments, but I "pay" afterwards (e.g. crash on the sofa when I get home, or need to slow down the following day).
> Frequently enough I've put in sustained 12-16 hour days for weeks on end to meet a tough deadline
I think many of us have done this here. What I've noticed from doing this is I start to make lots of mistakes that I wouldn't normally. At a certain point, this turns into a vicious cycle where I think slower and make more mistakes so I need to work more to fix them.
Maybe you're superman and can really work all those extra hours at full concentration...but probably not.
Here's an easy way you can check. Use a timer and throughout the day start the timer when you are going into work that requires full concentration and then stop it when you're done or someone interrupts you or you need to go to the bathroom or you break off from your task. Meetings and emails don't count.
I think you'll be surprised at the results.
There was an academic paper a few years back "The role of deliberate practice in the acquisition of expert performance" ( a nice summary here - http://blog.vivekhaldar.com/post/3881908748/tldr-summary-the...). The paper breaks down 3 types of activity: work, play and deliberate practice. Work is exercising skills you already know; Play is creativity, fun, exploration; Deliberate practice is building a skill - where expertise is achieved through focused training in a particular skill. The article suggests there is evidence that it takes about 10yrs to acheive expert status in a skill. Malcom Gladwell introduced a similar topic through pop-sci writing "Outliers" - suggesting there was evidence that becoming an expert required 10k hrs of practice.
To me, practice requires the absolute most concentration - unlike 'work', with 'deliberate practice', by definition, you can't supplement skill with experience for efficiency.. to learn you have to evolve skill from more experiences. And I believe thats why the linked articuled a 'cognitive limit' of 4 hours by way of a violinist practicing in spurts of 2x2hrs=4hrs per day.
The last paragraph in the article talks about "four hours of intense concentration per day", and I'm not sure I buy that abstraction because "concentrating" and "training" are 2 different things. The author (and interviewee) is inferring that concentration is the constraint, but I'd suggest its more likely learning/trainability speed constraint.
So, a different interpretation, but I may be agreeing with you own observations. I think deliberate practice shows an upper bound for cognitive limit - but in the sense of new patterns being formed in the brain. I don't think deliberate practice necessarily shows the upper bound for concentration based on the information presented.
The article refers to mathematical work, which is by its nature very dense, much more dense than other intellectually-demanding jobs like programming. As a programmer, you might spend half an hour now and then thinking through all the potential race conditions in a parallel algorithm. But you don't do it non-stop all day, day in and day out. Most of your time is spent on things that require far less concentration.
I certainly agree it is tempting to read about four hours of concentration and use the article to justify four hours of mediocre work.
Break away from that and do something truly difficult - specification meetings where you're designing a process for huge pieces of hardware that haven't yet been built - studying something complicated and unfamiliar to you - etc - and perhaps you'll find - like me - that you've only got a few hours available to you before your brain turns to mush.
For a startup founder I think this is especially true. A lot of the things you do won't be very cognitively demanding. That doesn't mean you can skip it if you want to get anywhere. It doesn't even mean those 'menial' task create less value in your context than the hardcore 100% concentration parts.
Maybe when you've settled down to a predictable working pattern and managed to configure your environment to cater to all the necessary but trivial tasks (and create enough value in your 4 hours to pay for other people taking care of the rest) you can realize this. I'm not there yet.
It seemed to me that the research cited was likely a bit thin. I couldn't tune a guitar, so I have no idea about violin players. But there have been notable cases of very hard-working creative types--Flaubert and Sand come to mind, and Herbert Simon (Turing Award, Nobelist in economics) claimed that a 60-hour work week was about right for him.
I know if I'm going to have a shitty day or a great day the moment I wake up, the first interaction I have with a person (knowing this may make it more likely to happen, but short of that...).
I know when my brain is running on all cylinders, and when it's choking for more air. Tuning into these signals (I have no idea what they are, only 'feelings'), I can lay out the things I want to do in the next few days, and roll with the punches. It'd be interesting to see the amount of time idlers and time progressors (I'm at my computer most of the day, looking at my google search history would give a good indication - I generally don't google that much when I read articles on HN or Reddit, but when I'm doing something I'm googling up a storm).
No sense fitting a square key into a round hole when tomorrow the round key will be sitting in my hand.
When I'm really refreshed and interested and doing well and eating right I can pull all nighters and maintain work quality. I can't maintain this for extended stretches at all though.
For a sustained pace though, I agree completely with Mr. Cook and his sources that 4 solid hours a day is about right.
There are many people who put in substantially more hours and brag about it. A close look though nearly always reveals lots of meetings, busy work, and - these days - surfing the net, playing games, and flirting or shooting the breeze with coworkers. Remove all that and you seldom see more than 4 hours, and almost never 4 hours of solid work sustained for months at a time.
We should also consider whether this discussion is relevant to calls to extend school hours to 7 or 8 or more hours a day in the primary school classroom, as many are calling for. Does Finland, which has fewer school hours than the US, have better results because of it?
Also, with most work there's lots of things that need to do that require relatively little concentration once you've made the cognitive shift.
I think the four hour limit applies to design/creative work or work that requires immense attention to detail.
I'd say most people have little in a day that actively drains this reserve in more than a trickle.
I pull all-nighters regularly to work on personal projects, and managed to push out 4-6 hours of concentration during them after a full day work, but the key to that for me (with the caveat that I'm close to 38, and probably could push through more when I was in school, but on the other hand I know how to pace myself far better):
- I nap 1-2hour in the evening, after dinner, and then take a 1-2 hour relaxation period where I'll vegetate totally in front of the TV or listening to music punctuated by low-concentration tasks such as making a list of what I hope to achieve (with estimates and times at the night where I hope to get to them, which makes for a hilarious lesson in how bad we are at reliably estimating stuff...)
- I pump myself full of caffeine (usually about 200mg, my caffeine sensitivity is really low) and b-vitamins, and "dripfeed" myself sugar.
- I'll use modafinil to retain alertness when I go off for work the next day.
- I'll go to the gym but focus on cardio, stretches and time in the steam room and make sure I have time to take "the slow train" which gives me a 30 minute nap during my commute.
- I'll make sure to take a proper relaxing lunch break. Sometimes I'll go find a park bench and sit and nap or meditate for half an hour.
- I'll make sure to schedule my daytime work to the times that works best for me, and try hard to get some extra high concentration work out of the way on the "before" days, and do more "menial" tasks on the "after" days to ensure the overall effect on my daytime job is minimal (overall I think I actually end up with a net benefit, as the personal projects I work on generally are learning experiences that are often synergistic to what I do during the day).
- I crash totally the next evening - usually going to bed at 8pm and sleeping until 6am the following day. Everything in my scheduling is geared towards keeping me productive the following day too, but with the expectation that the evening will be totally lost.
- If I at any time see my productivity start slipping at night, I go to bed. If I see my productivity start slipping in my day job, I take a week or two break from this schedule and get to bed extra early, because I know if I don't I'll tend to get into a rut where things take longer and tire me out more, prompting me to get stupid ideas about working even longer. And I never, ever do more than one or two of these a week...
In the end, I'm not gaining any hours per se, but the hours I get are hours where I'm more productive (the alternative for me was taking e.g. 8pm to 11pm on evenings where I'd still be tired and generally wouldn't concentrate well at all). The structure of a nap, slowly easing into it, and then focusing totally while the house is entirely quiet works very well for me. Probably isn't healthy in the long term, though. But I need me time desperately to stay sane (got a 3 year old that otherwise occupies all my time at home when he is awake).
It's a massive hassle just to get that extra block of concentrated time (now, if I could afford to slack off the entire following day at work, it'd be a lot easier :) ), but it feels worth it at the moment. When my son gets older and demands less of my time so I get more time to myself earlier in the evening, I very much doubt I'll keep this up (though I've grown attached to taking 1-3 hour naps in the evening and working a bit into the nap instead, so that I'll probably keep up to some extent)
I also did the same study plan for the bar exam and feel like it worked well there too, i.e. passed it on the first try with a minimum of drama, the whole thing was actually quite pleasant.
In contrast, many of my peers would study basically around the clock, pull all nighters, made their lives miserable and didn't do any better, and more often than not quite worse.
My take away from the experience was that 8 hours of real work is really a lot of work. And distractions are absolute poison: internet, cell phone, etc. Nothing quite like locking yourself in a room with just a book and highlighter--no computer, no cell phone, no people. You add those things to the mix and it can easily take a 16 hour day to get 8 hours of real work done.
It's interesting that we see so many articles posted on hacker news on how to be more productive, beat procrastination and be more motivated when really this article the OP posted explains it all. In most cases you probably don't have a problem with procrastination and motivation, it's simply that you are over-extending yourself. Cut back your commitments and you fix your problem.
The one actual job I had as a web developer set the work week as 40 hours a week (8 hours a day.) This left me wondering if any developers actually work this long of a day and how they could possibly do it.
When I'm doing client work, I'm ON, all the circuit boards are lit up. I can't keep this going for more than 4 - 6 hours per day. If I work a long day, then the next day I'm drained and I have to pay off that debt.
It actually took me years to really figure this out after a life of being trained to the 40 hour work week (parents, my early work life.) The 40 hour model for work is broken.
Does this mean that each of us has a reservoir of about 4 hours of intense concentration per day? When we perform a less-intense task, like driving or facebooking, are we using those 4 hours at a reduced rate?
This sounds like it could feed into another idea - that each human has a limited number of actions per day. Performing actions costs concentration, and so we pay for each action from our concentration reservoir?
Further, he suggests that each of the 100k may require 100 pattern recognizers in neo-cortex. That means, the brain needs to configure 10 million patterns in total - these are either newly observed, or new relations formed with existing patterns.
I'm sure its not linear, but if you divide 10M patterns by 10k hours, that means the neocortex needs to add an average of 1 pattern every 3.6s, or 4k patterns per every 4 hours (ie, limit for day). Thats about 400k neurons / day re-purposed for learning through deliberate practice to learn 40 board positions / day in chess.
Continuing the conjecture, what we know about about spaced-repetition and mass-repetition might provide some nice bounds for upper limit on how these neurons can be exposed to learning material over 4-hr period to optimize their use as pattern recognizers.
Could make a nice illustrative simulation to speculatively address your question about limits of concentration / learning reservoir.
I think we overestimate how quickly we can really context switch. It's interesting to look at how people respond to stimulants. People take adderall to "help them focus" but what it really does is magnify what I think is a latent resistance to context switching.
Yes - there are days I can do more. But there are also days I do less than 4 hours. In the long run I do about 4 hours a day. That's it.
One of Adams' books has a story about someone who took 2 simultaneous jobs at one company. He would show up early on one floor, then take an early lunch and head upstairs to his other job, where they thought he was just arriving late. The employer did eventually catch on, but until then he was paid 16 hours of work for 8 hours of his time.
This really bugged me early on in my career before I understood this. When I started work I would feel disappointed that I couldn't be productive for 8 hours per day. Then I realised that no one else around me was getting probably more than 3 hours of work done in a day so I set my aim for each day at 4 hours of productivity and used a timer to track my concentration time.
I still feel conflicted by it though. When I was freelancing, I tried doubling my rate with the expectation that I would only work 20 hours per week. I think most people thought I was lazy and wouldn't go for it. Hopefully in the future we'll be able to move away from the idea that a 40+ hour work week is ideal.
Eg you could say you'll only be working 20 billable hours per week and suddenly it sounds like they will be getting some of your time for free.
The rest of the time is actually taken up with marketing, administration, training etc.
I could quote a fixed price for some work, and they'd readily accept my rates. But if I then would try to leave after the amount of time the work actually took me, they'd question whether or not I was actually doing the job properly.
So I quoted even higher on the expectation that 1) I'd have to sit in a chair in their office 8 hours a day and so couldn't do other work elsewhere and needed to be compensated extra for that inconvenience, 2) I'd be bored out of my mind trying to fill the rest of the time I was there.
Never a question raised.
It was frustrating. Especially one job where I as stuck for 3 weeks on a machine with no internet connection doing a job I could easily finish with 2 hours every day. Whenever possible I'd work remotely.
I also agree it is possible to do longer bursts, but that is pretty rare in my experience.
"Your Brain At Work" points out, among other things, that the brain is capable of doing much less intensive work (as in, concentration) than most people believe it is.
I wouldn't do it for a job, though. I think that can only be done for love.
Since then I've read of luminaries mentioning this in passing, but I haven't really tried to employ it. (I'm also pretty sure I've seen pg say this is empirically false with YC founders, and perhaps he and axiom are correct)
I'd like to know if there's evidence of this for learning, however, even if it is mathematics.
At best you might recruit some undergraduates -- nearly all psychology subjects are college students -- and have them do some artificial task one way or another for a couple weeks. I find anecdotes from successful musicians, scientists, and authors more persuasive than data from an contrived scientific study.
I would have learned a lot with 4 hours a day, but I think the extra 90 hours I put in that month really helped me out.
From what I've seen, most employed programmers only spend about this much time (maybe a bit more) actually programming.