Electric brain stimulation decreases IQ scores and racial prejudice
kurzweilai.net
kurzweilai.net
tDCS is believed to enhance learning by providing more force behind the encoding of memories: it's like pressing harder when writing with a pencil, making it harder to erase. Normally it takes many iterations of practice to encode a complex skill properly, but with more electricity behind the "write" operation it takes fewer iterations.
However, with perceptual reasoning, encoding memories quickly would be counterproductive, because it would cause your first ideas to be firmly encoded, leading you to consider fewer ideas. This would prevent the broader considerations necessary in problem-solving.
I'm not a neuroscientist, so take what I'm saying with a grain of salt. I've just read a lot about tDCS, and have no formal training.
Personally, I find the idea of wiring my brain, my self, up to something which zaps it with little to no understanding of the underlying science or function scares the bejesus out of me, and strikes me as a strange at best and stupid at worst thing to do.
Ah, let me just pop a leech on this, it'll get my phlegmatic humour rebalanced.
I'm actually not so surprised by the racial prejudice effect. Many low-IQ people I've encountered are execeptionally friendly, accepting, and non-judgemental. Not to say that is evidence of anything, just my experience.
Not before some wag jumps on it and makes sure anyone who tries to discuss the topic rationally and thoughtfully is already seen as racist and stupid.
I dream of a community where everything is up for discussion, even if I disagree with it.
"Hurry! Before anyone has a simple thought in their head, brand them as racist and misogynist!"
I'm also not sure where you got that I'm trying to censor discussion - you commented, did you not?
"michas 3 hours ago [dead]
It has nothing to do with intelligence, it is just all about being realist. Existence of different races comes from the fact that there are genetic differences between people. It would be stupid to assume that those genetic differences have no other effect than skin color."
Respectfully, I think you're reading into it too much.
1. Individual variation in intelligence dwarfs any population level measure with regard to race. 2. The evidence with regard to IQ differences by race is suspect at best, especially because it is unclear that one can accurately control for socioeconomic factors. 3. It would be ignorant to assume that transporting an entire people from one continent to another, forcing them to serve as slaves for much of our history, systemically suppressing their political representation even after granting freedom, and an extremely efficient police-prison-industrial complex that disproportionately targets that minority would leave no lasting ill effects.
It suggests to me the motive is a writer's true belief is in racial superiority, which given the hellbanned account, seems the more likely option than an honest attempt to further a scholarly discussion.
You seem like someone with an axe to grind.
I was talking about people making a causal link between elevated intelligence and incidence of racism - not even slightly that there were cognitive differences between "races".
"In the U.S., blacks are 12% of the population but commit 50% of violent crimes; can anyone honestly think this is unconnected to the fact that they average 15 points of IQ lower than the general population? That stupid people are more violent is a fact independent of skin color." -Eric S Raymond
It is hard to call something classic if you censor it until it no is no longer seen, heard about, or known.
"A black man with an IQ of 85 and a white man with an IQ of 85 are about equally likely to have the character traits of poor impulse control and violent behavior associated with criminality — and both are far more likely to have them than a white or black man with an IQ of 110" -Eric S Raymond
Beside from that, the title suggests something like a causal connection when they just found it correlating on a sample of 60 persons? Seriously?
This study is utter bullshit.
n=60 is actually pretty big for this kind of study (most cognitive studies involving fMRI, for instance, hover around n=20). Either way, simply looking at the sample size is deceiving, as statistical power is what matters in the end. If sufficient power can be achieved with 60 persons, then yours is not a valid criticism.
Concerning the design, this is a straight-up experimental manipulation and not just a correlative study. There were two groups, one which received real tDCS and the other which received a sham tDCS. Subjects were assigned to each group in a double-blind fashion, and the measure of interest here is the improvement between the first test (pre manipulation) and the second test (post manipulation). The use of a sham rules out any placebo/nocebo effects.
This is exactly the kind of study that one would design in order to test causality. We have both temporal precedence and covariance; together, these strongly suggest that tDCS is responsible for the observed effects.
A correlation in your sample (especially at that size) does not imply a correlation in the population, even if you validate it with additional sham tests.
The study performed statistical hypothesis testing to determine that the means of the two groups are probably different.
Edit: and more to your point, correlation of the sample implies correlation of the population if the sample is representative. Is this the case for this particular paper? I don't know and neither does anyone else; that's why replication is the gold standard of scientific validity.
At least quote the article correctly.
> That is, correlation in the data you happen to have (even if it happens to be “statistically significant”) does not necessarily imply correlation in the population of interest.
(Emphasis mine)
Otherwise you might as well throw out centuries of mathematical, statistical and scientific progress. That laptop of yours? Throw it in the trash as it is the culmination of thousands of sham tests and correlations and is therefore clearly impossible.
60 is plenty if the effect is large enough. Hey, even n=4 can make for a good study. Give two of them cyanide and two of them a placebo, let all the trial-size-too-small-correlation-isnt-causation-people watch and then ask them to back up their criticism with a nice helping of the tested substance.
"... if the effect is large enough"
If the sample is representative (and they don't even claim ot attempt to study something that would only affect a particular group) then 60 are fine, in fact they could do with even less.
Besides, what correlation? This is direct observation, there's no other parameter in play in the test setup.