
Human behavioral complexity peaks at age 25: study - Hooke
http://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1005408
======
xux
Did anyone even read the article. The study has nothing to do with complex
behavior or "sophisticated" behavior. It's a study on your ability to generate
random list of results, like "listing the hypothetical results of a series of
12 coin flips so that they would 'look random to somebody else'"

~~~
gabrielgoh
it appears to be a way to measure complex behaviors, and higher cognitive
functions, however - so I don't think the commenters are that far off.

~~~
red_hairing
I would call this test an analogue of IQ testing. Again, we see how mainstream
thought places IQ on a pedestal. Mainstream thinking overvalues and overrates
mental gymnastics, such as performance on IQ testing. But learned experience
is in my opinion far more valuable and should be valued more by mainstream
thought. At age 60, it is true that I cannot perform as well on IQ tests. But
in my opinion my understanding of the world is much greater. I was like a
child at age 25, even though I tested well on IQ tests. But I was just a
child. Does mainstream scholarship explore this facet of human development?
Not much....

~~~
vslira
Isn't the lower scores for older people just a result of the flynn effect?
This doesn't mean a personal drop in "absolute" g, if it's really a thing

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WilliamDhalgren
yeah, but apparently barely declines untill say 60+. Speed suffers however.

"The adult years were remarkable in that complexity remained at a high level
for a protracted period, in spite of a slow decrease of speed during the same
period. This suggest that during the adult period, people tend to invest more
and more computational time to achieve a stable level of output complexity.
Later in life (>70), however, speed stabilizes, while complexity drops in a
dramatic way."

and

"These speed-accuracy trade-offs were evident in the adult years, including
the turn toward old age. During childhood, however, no similar pattern is
discernible. This suggests that aging cannot simply be considered a
“regression”, and that CT (completion time) and complexity provide different
complementary information. This is again supported by the fact that in the
25–60 year range, where the effect of age is reduced, CT and complexity are
uncorrelated (r = −.012, p = .53). These findings add to a rapidly growing
literature that views RIG tasks as good measures of complex cognitive
abilities [21, for a review]."

~~~
derefr
It almost sounds like people try harder and harder to keep up with societal
expectations of continued "sharpness"... until they hit some age where
cultural norms say they aren't expected to be sharp any more. And then they
stop trying, which causes an outsized decline as their lowered expectations of
their own capability, feeds into lowered capability, which feeds back into
further-lowered expectations.

~~~
WilliamDhalgren
could be, I really don't know. I can imagine perfectly benign scenarios too;
if our long-term memory grows with time, maybe there's just more possible
connections/associations to filter out with time too, so that decision just
becomes harder, with only the deeper old age being simply tissue decline, the
exhaustion of cognitive reserves etc.

Somewhat relatedly, I think I heard on some old Skeptic's guide to the
universe episode about an experiment with some nootropic, maybe it was a
racetam though I think it was mondafinil, and this kind of reaction time to
response accuracy tradeoff was observed, on young healthy adults. Those with
less correct answers slowed down, presumably concentrated better and gave
better answers, but those already good at whatever the task was simply were
slower and yet no better.

~~~
copperx
Is it possible to get a link to that episode?

~~~
WilliamDhalgren
ah, I'm sorry but I really don't remember. this was some years back.

~~~
tim333
Maybe
[http://www.theskepticsguide.org/podcast/sgu/530](http://www.theskepticsguide.org/podcast/sgu/530)

[https://www.sgutranscripts.org/wiki/SGU_Episode_530](https://www.sgutranscripts.org/wiki/SGU_Episode_530)

?

~~~
WilliamDhalgren
hey, that's not bad; didn't even expect SGU had such detailed transcripts.

But actually looking for it now, the particular study I had in mind seems to
be from a science or fiction segment from this episode:

[http://media.libsyn.com/media/skepticsguide/skepticast2014-1...](http://media.libsyn.com/media/skepticsguide/skepticast2014-11-22.mp3)

Interesting to see how Steve's assesment of modafinil evolved between the two
episodes

~~~
copperx
Thank you so much for your time. I was really curious.

------
noobermin
Ok, comments on fig. 2.

The 95% confidence intervals are plotted, but clearly the distribution of
their subjects seems to sample heavily near where they find their peak (~25 to
40 ish), and correspondingly, the drop offs are away from that area...

Seems fishy to me.

~~~
joveian
Also, if you look at the right side of figure 1 there are lines on the bottom
of the complexity chart for each of the tasks, presumably representing people
who essentially did not do the task (although they still seem to have spent a
variable amount of time not doing the task). It looks like this skews older,
and just by eyeballing the chart some of the 75+ would be upward trends if not
for that bottom line. I skimmed the article and did not see a discussion of
this.

~~~
BlackFly
Furthermore, the poor sampling near the edges of the plots leads me to suspect
that the trend away from a flat line is due to Runge's phenomenon. The peak
may be nothing other than the oscillations from this phenomenon leaking into
the interior of their data set.

------
transverse
I am conducting a survey as a first attempt to see what's going on. If you
would be so kind, please take it here:

[https://j.mp/CoinFlippingSurvey](https://j.mp/CoinFlippingSurvey)

If I get about 100 more respondents, I will release the data and analysis at
the same link.

~~~
woliveirajr
It's not easy to click to the left or to the right 128 times. Can't you just
replace it with a textbox where users type T or H, or something like that ?

~~~
transverse
I agree. It is so much easier and quicker on a smartphone though.

The survey is intentionally dumbed down so non-technical users don't have to
type much. You can almost say it is geared toward the general population, many
of whom use smartphones.

------
windlep
I wonder how/if this relates to the fact that many mental illnesses fully
manifest around 25 as well.

"Roughly half of all lifetime mental disorders in most studies start by the
mid‐teens and three‐fourths by the mid‐20s." \-
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1925038/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1925038/)

~~~
derefr
A large part of this is that doctors are wary to diagnose mental disorders in
children/teenagers, though. Often, symptoms of mental illness during
development are just the brain doing the neurochemical equivalent of "one leg
growing faster than the other"—it ends up balancing out.

There is still some element of truth to this, though, especially with bipolar
disorder and psychosis. It puts me in mind of the fact that _allergies_ can
also manifest around 25... and makes me wonder if there's a connection there.

~~~
Lownin
FWIW, I developed a rather severe allergy to many types of fish out of nowhere
at 31.

------
nabla9
Authors' Reddit AMA:

[https://www.reddit.com/r/science/comments/6accnw/plos_scienc...](https://www.reddit.com/r/science/comments/6accnw/plos_science_wednesday_hi_reddit_my_name_is/)

------
twiss
In high school, my math teacher once asked us to write down a random string of
zeroes and ones, similar to what they did in the study to measure "cognitive
functioning". He then asked us to count the number of times we alternated
between 0 and 1. He told us that while most people try to have about a 50%
split between 0 and 1, many alternate too often (0101101 instead of 0100011).
Maybe there are other tests that one could learn to improve one's randomness,
or at least write down a random string faster (they also measured speed).

In the introduction, they cite that "the complexity of a subject-produced
pseudorandom sequence (…) is surprisingly resistant to practice effects".
However, is it also resistant to teaching effects?

~~~
trevyn
This is a great question. What are the speed requirements?

[https://www.quora.com/Is-it-possible-for-a-human-to-
generate...](https://www.quora.com/Is-it-possible-for-a-human-to-generate-a-
truly-random-sequence-mentally)

You could probably come up with a reasonably good, fast mental PRNG algorithm,
and practice that.

~~~
Someone
Pick a phrase (name, address, phone number would do), discard white space, and
convert the upper two bits to binary.

Example: "Pick a phrase" would become

    
    
      00 01 11 11 01 00 00 10 01 11 01...
    

That's certainly not random, but unlikely to be detectable for shorter
sequences.

(Edit: it probably is a fun exercise to write a program that decodes this code
that reaches >75% (lossy) compression)

~~~
averagewall
That would hurt you on speed. It's much faster to just pull numbers out of
your head as fast as you can write them down. That should be protection
against using an algorithm. Even if you do have a fast algorithm, it would
still get slower as you age, so you could use it to compare yourself at
different ages.

The test might also be scored using randomness tests that would pick up the
repeated use of the same algorithm, like the one you described. Distribution
of letters and their (ASCII?) bits won't be perfectly random. You could also
hand code exceptions for known algorithms as you discover them.

That's what interests me. Monitoring your own cognitive ability as you age for
early detection and tracking of neurodegenerative diseases. For this, you need
a test that's resistant to practice.

~~~
Someone
_" It's much faster to just pull numbers out of your head"_

I don't doubt that, but the context was to generate reasonably good (in the
sense of "looks like independent samples from a 50/50 distribution")
sequences.

Humans are notoriously bad at that (example: in the first 9 bits, one would
expect four consecutive zeroes or ones. Try finding someone who produces that
when 'just pulling numbers out f their head as fast as you can write them
down').

I think this will be significantly better (as indicated above: for shorter
sequences), even though it lumps a, e, i, n and r to the bit pattern '01'. It
also can be quite fast, even if you do it by memorizing the mapping from
letter to 1..26 doing 'mod 4', and conversion to two binary digits.

------
docere
Perhaps this has something to do with completion of myelination to the frontal
lobes.

~~~
nkjoep
FWIW, I've been discovered with MS exactly at 25.

------
Rasco
Previous discussion :
[https://news.ycombinator.com/item?id=14131086](https://news.ycombinator.com/item?id=14131086)

------
futun
I completely believe this. I was far more sophisticated in my late 20's.

In my late 30's I learned to stop being such a douche... and I became far
simpler.

We all see through the Matrix as we get older...

------
ue_
I'm 20 years old in my first year of university, and I'm probably going to
fail the final exams next week. I don't think I'll be having the chance to
take advantage of this peak.

~~~
mikekchar
When I was in first year (a long time ago), the computer science department
was quite new. This meant that courses were held in various different places
-- engineering, science, math, etc. Unfortunately, this ultimately meant that
I had to pass by the campus pub between every class, with predictable results
(drinking age where I lived was 18).

Whether you pass or whether you fail will not have as big an impact as you
think now. What is important is understanding how to improve. For me, I staked
out a chair in the library with all the foreign students who seemed to live
there. I got in to school at 7:30 am and I went home at 5:00 pm. I watched
what all those foreign students were doing and copied them.

Later talking with them, I discovered that the reason they lived in the
library was because their tuition and living expenses were covered by their
extended family. You'd have 20 people sending money that they really couldn't
afford just so that _one_ person might get a foreign education and a high
paying job to lift everyone out of poverty. If they failed their exams, people
in their family would likely die of disease, etc as a result.

So I don't know anything about your situation, but probably it's not as bad as
what my friends in the library had to endure. You've got a week. It might not
be enough time to salvage first year (like I said, been there, done that). But
use that time to understand what you need to do from here. Go to the library.
Pick out a seat where you intend to live. Today is a good day to start to see
what you can do.

~~~
Cyph0n
Excellent advice.

At the end of my first semester at university, my Calc I professor pulled me
aside after class for a chat. We talked about a bunch of things, but one piece
of advice in particular stuck with me.

He said: "You are lucky to be so privileged - to study at a university for
free, to have a supportive family, and to be such a smart and capable student
- but you are also quite unlucky. Unlike other less privileged students around
the world, you need to create your own drive. Without motivation, you'll have
a tough time overcoming the inevitable difficulties you'll face in the
future."

So that's what I ended up doing. Firstly, I started to imagine myself being
from a much less fortunate background, and therefore treated my studies as a
matter of utmost importance. And secondly, I put a target in my mind for what
kind of person I want to be in the far future. I visualized this in quite a
bit of detail, sometimes even imagining myself being interviewed! (weird, I
know)

A little over 5 years later, I'm in a top 10 PhD program in my field. I'm
still not certain this is what I want to do for the next 4 years, but I think
I'm on top of it for now. Worst case scenario is I drop out with a MS and
enter the workforce. Still, I'm immensely thankful that I have the option to
think about this. Many people don't.

~~~
ue_
That's an interesting story, though I find that I oscillate between periods of
perceived dread (though, as your Calc professor mentioned, I am privileged in
this regard to not have it as much of an issue) and periods of a kind of laid
back-ness in which I procrastinate and put things off as much as they possibly
could be put off. This has been a recurring problem for me, possibly because
the enjoyment of playing games or watching TV is an instant relief and
pleasure.. the years of my life after university are distant and contingent.

On one hand I know that I need to work in order to get anywhere, on the other
hand I pass it off by saying "you don't have to do this work to succeed".
Couple this with the fact that whenever I want to start working there's a huge
mass of things to choose from and I don't know where to start with it, or that
I have very little willpower to stay with a question if I don't make progress.

It's hard, and I fear I may never learn. I tried to study in the library but
alas no habit formed, even after a few weeks. I had diminishing returns by
doing that.

~~~
math_and_stuff
One trick for breaking that is to get addicted to improving your craft. For
me, it was originally starting an open source project, but there is something
magical about a cup of coffee, a big stack of paper, and a math book that you
have just the right prerequisite knowledge for.

~~~
ue_
My problem may be that I don't have much passion for the subject I'm studying
(electronic and computer engineering), as I originally applied to do a
different degree. Although I find some parts of the subject interesting
(digital systems, perhaps some mathematics), others I find hopelessly hard
(analogue electronics and physics). A bad part is that I don't even have a way
to evaluate my knowledge against the standard which is expected of me; the
course is new, and the past papers contain material which may or may not be
relevant or taught before. Could I have an impostor syndrome, or do I really
not know enough?

Motivation may be what I need, or perhaps it is discipline? I can't stick with
things. I will relate an example without hyperbole; today I was trying to find
three unknown variables in three equations (A), using matrices first by
combining with the identity matrix (I), as (A|I), then forcing zeroes into the
bottom left and top right corners of A, and dividing through to transform A
into the identity matrix, what is left is A^(-1).

I repeatedly failed to get the correct answer, probably due to some silly
arithmetic error. I gave up and started to watch old episodes of Simpsons and
read HN.

~~~
NamTaf
Do some reading on how to develop willpower. Although I'm not a fan of the
rest of the site, I found the Art of Manliness did a decent 3-part on how to
cultivate willpower and hone it into productive pursuits.

I had it super easy in school. I was gifted enough to coast through with no
study whatsoever. It was basically just an organised social life for me. Same
with first-year uni, because school had taught me enough to coast through
that. Come second year, however, it was new material and it wasn't forced down
my throat with the structure that school provided. I crashed and burned
miserably, failing 1 subject and barely scraping through 2 others (i.e.: pass
by 2-3%).

It took me until 4th year to teach myself how to teach myself, and how to
develop that discipline and willpower necessary to stay focused on a goal. It
also took that long to learn _how_ I learn, that is whether I learn best
through reading lecture notes, watching examples, doing problems, etc. You're
never really taught any of that at school, but you're expected to know it by
uni to do self-guided learning. It's a hard ability to pick up, too.

With your example, I'd encourage you to watch some Khan Academy lectures.
Maybe listening to and watching exmaple problems works better for you than
reading textbooks or lecture notes. Additionally, maths is in particular one
of those things where tonnes of practice problems will help reinforce it until
it just 'clicks'. In isolation the processes may seem simple as you watch
them, but the practice is what helps you identify the underlying patterns and
thus know which technique to choose when, and how to identify that you've
executed the technique properly.

------
known
Poverty May Affect the Growth of Children's Brains
[https://science.slashdot.org/story/15/03/30/2159247/poverty-...](https://science.slashdot.org/story/15/03/30/2159247/poverty-
may-affect-the-growth-of-childrens-brains)

