Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Is full-time work bad for our brains?

bbc.com

Post reply on HN
Print view View original

201–210 of 229 posts

Re: Is full-time work bad for our brains?

#201

Post by [deleted] »

psychometry wrote: post #194
DaniFong wrote: post #192

Earlier quoted context omitted.

I'm sorry, I am trying to explain something that is very clear in my head, and I'm pretty sure that I'm right, but I haven't had bio-stats training specifically so I do not know the language precisely. My background is in physics, computer science, and epistemology. The functions I am referring to are estimators of cognitive indicators (like backwards digit span, say, that they use in the paper), as a function of wor…

There's nothing wrong with the inclusion of a quadratic term in a linear model if the variable is significant, which is clearly is according to Table IV. You can't just plot a single predictor against the sample outcome and expect the plot to be particularly revealing in multiple regression. Plus, this isn't even multiple regression; this is a two-stage least squares multiple regression. The working hour (WH) variabl…

[deleted]

Re: Is full-time work bad for our brains?

#202

Post by DaniFong »

psychometry wrote: post #194
DaniFong wrote: post #192

Earlier quoted context omitted.

I'm sorry, I am trying to explain something that is very clear in my head, and I'm pretty sure that I'm right, but I haven't had bio-stats training specifically so I do not know the language precisely. My background is in physics, computer science, and epistemology. The functions I am referring to are estimators of cognitive indicators (like backwards digit span, say, that they use in the paper), as a function of wor…

There's nothing wrong with the inclusion of a quadratic term in a linear model if the variable is significant, which is clearly is according to Table IV. You can't just plot a single predictor against the sample outcome and expect the plot to be particularly revealing in multiple regression. Plus, this isn't even multiple regression; this is a two-stage least squares multiple regression. The working hour (WH) variabl…

"You can't just plot a single predictor against the sample outcome and expect the plot to be particularly revealing in multiple regression"

Isn't this, effectively, what they are doing when they say they have found an optimum number of "working hours" for one to work to maximize cognitive indicators?

I'm not even quibbling whether they're demonstrating causality versus correlation. The problem is that their result and the number that they found are likely artifacts of the method of the analysis, and the choice to include only linear and quadratic terms.

Re: Is full-time work bad for our brains?

#203

Post by [deleted] »

psychometry wrote: post #194
DaniFong wrote: post #192

Earlier quoted context omitted.

I'm sorry, I am trying to explain something that is very clear in my head, and I'm pretty sure that I'm right, but I haven't had bio-stats training specifically so I do not know the language precisely. My background is in physics, computer science, and epistemology. The functions I am referring to are estimators of cognitive indicators (like backwards digit span, say, that they use in the paper), as a function of wor…

There's nothing wrong with the inclusion of a quadratic term in a linear model if the variable is significant, which is clearly is according to Table IV. You can't just plot a single predictor against the sample outcome and expect the plot to be particularly revealing in multiple regression. Plus, this isn't even multiple regression; this is a two-stage least squares multiple regression. The working hour (WH) variabl…

[deleted]

Re: Is full-time work bad for our brains?

#204

Post by xapata »

DaniFong wrote: post #193
xapata wrote: post #189

Earlier quoted context omitted.

The coefficient for the squared component could easily be zero. This is called "not statistically significant". There is no guarantee for a parabolic shape.

The measure of possible data sets where, by standard statistical analysis, the coefficient for the squared component is zero, is tiny. There's no guarantee for a parabola, just a very high degree of certainty. Your other point, that the parabola could be "not statistically significant," is true. But given a strong degree of significant correlation between unemployment and the cognitive indicators, even if the depende…

> is zero

Sigh. No coefficient is ever exactly zero, just very close [0]. I didn't think I needed to explain that when writing, "could be zero."

> you will still get a parabola

If the squared parameter is not statistically significant, the author will likely drop it from the model. In that case, we would not see a parabolic model and the paper wouldn't exist. The authors would have moved on to a different topic, or found a different dataset.

If the coefficient is so small that it is indistinguishable from zero (not significant), then we ignore the associated variable entirely. To do otherwise would require us to discuss an infinity of possible variables as if they mattered to the model.

> correlation between unemployment and cognitive indicators

If you're arguing that the author should have dropped all observations of unemployed persons from the dataset, that's completely separate and has nothing to do with parabolas.

[0] "ever" loosely defined.

Re: Is full-time work bad for our brains?

#205

Post by xapata »

DaniFong wrote: post #191
xapata wrote: post #172

Earlier quoted context omitted.

I skimmed the paper and couldn't find this "critical mistake". The nonlinear model you describe is common and appropriate to situations like this. y ~ x + x^2 A mistake would be y ~ y^2 And even then, it would be appropriate if we're modeling an autoregressive process. y_{t} ~ y_{t-1}

I'll try to state in this language what I think is the conceptual flaw. The stated conclusion is "there is an optimum number of work hours, and it is less than 40." However, their method of analysis is this: "We fit a non-linear model that is a quadratic model cognitive ability y ~ ax + b x^2 for x work hours / week, and we found a statistical optimum around 25 hours" The problem with this is that you're trying to fi…

> Because there is a fairly strong correlation with unemployment and cognitive indicators

You're arguing that there's an endogeneity effect -- that poor cognition causes less working? That's a common problem. The authors discuss their use of an instrumental variable technique to avoid this issue.

> parabola is already being "forced down" near hours worked = 0

Not sure what you mean. Typically a model like this includes a constant to allow for a non-zero dependent variable when all the explanatory variables are zero. To do otherwise in this case would be absurd. The idea that the average non-working person has zero cognitive function...

> smooth, quadratic curve, is a mirage

Ever heard of a Taylor polynomial?

Re: Is full-time work bad for our brains?

#206

Post by jacalata »

Mahn wrote: post #31

Could it be that there is some selection bias in this study? I don't mean to say the conclusions are wrong per se, but I would think that people working very few hours (unemployed?) or too many hours (factory workers?) are typically less educated than those in the middle, which could explain the IQ disparity.

Over the last few decades longer hours have become associated with higher earnings and higher educational backgrounds http://www.nber.org/digest/jul06/w11895.html (old data but a good start)

Re: Is full-time work bad for our brains?

#207

Post by madaxe_again »

dredmorbius wrote: post #183
madaxe_again wrote: post #159

Earlier quoted context omitted.

Can't sell except for the aforementioned £60. Not £60k, £60 - the nominal value of the shares. The only way I can leave and keep my equity is if I die. If I attempt to have that conversation in a board meeting they'll know what's up and will probably fire me - in which case no severance, not even the £60. There's a third party hnw investor who came in a few years ago who's gone from arms length to "where the fuck are…

Talk to a lawyer. How the hell did you end up with an equity share with net value to you of £60?

Nominal value. Fair market would be several million. If I leave for any reason other than death I get the nominal value.

Re: Is full-time work bad for our brains?

#208

Post by dredmorbius »

madaxe_again wrote: post #207
dredmorbius wrote: post #183

Earlier quoted context omitted.

Talk to a lawyer. How the hell did you end up with an equity share with net value to you of £60?

Nominal value. Fair market would be several million. If I leave for any reason other than death I get the nominal value.

Point remains that terms of yor departure are largely controlled by the firm, not you. Including making conditions so untenable your only rational option is to leave.

Again, a solicitor should be able to give you more specific advice.

Re: Is full-time work bad for our brains?

#209

Post by ZenoArrow »

alatkins wrote: post #195
ZenoArrow wrote: post #171

Earlier quoted context omitted.

> "It's your body's natural response to having been fed - conserve energy until the next hunt." I think it's more likely to be due to the energy it takes to break down food (meaning you have less free energy) that causes people to feel sluggish after a large meal.

It might be dependent on what was eaten. Of you eat a carb-heavy meal, and you are very insulin-responsive, then you can feel tired afterwards. Try skipping carbs at lunch, stick with protein+fat, see if that makes a difference.

I don't personally have this problem, even with carb-heavy lunches, but thanks for the advice.

Re: Is full-time work bad for our brains?

#210

Post by sethammons »

jdc0589 wrote: post #27

My brain usually goes in to "prepare to shut-down" mode every day at about 3:30pm (having started work at ~9am). I tend to have slow mornings, and stay pretty busy/head-down for the last half of that time. The funny thing is, it doesn't really matter if I was busy working on hard technical challenges all day, or just reading articles/browsing the web; my brain shuts down the same time regardless.

I used to get the afternoon doldrums. This stopped when I cleaned up my diet (little in the way of refined carbs, mostly no sugar, higher protein, more vegetables) and began regular exercise (crossfit). Now, I may get an afternoon slowdown once every few months (usually from not enough sleep).
Post reply on HN