from your link: "The American Psychological Association's report Intelligence: Knowns and Unknowns stated that in the United States IQ tests as predictors of social achievement are not biased against African Americans since they predict future performance, such as school achievement, similarly to the way they predict future performance for Caucasians."
so the consensus in psychometrics is that iq tests are not systematically biased against particular groups.
and of course it measures a lot more than a person's ability to take intelligence tests". just look at the "social outcomes" section of the wikipedia page...
> The American Psychological Association's report Intelligence: Knowns and Unknowns stated that in the United States IQ tests as predictors of social achievement are not biased against African Americans since they predict future performance ...
The flaw in the reasoning should be obvious to anyone but a psychologist -- the test outcome becomes a self-fulfilling prophecy, rather than an unbiased predictor of future performance. The contempt for science among psychologists is shocking.
> so the consensus in psychometrics is that iq tests are not systematically biased against particular groups.
Psychologists also came to a consensus among themselves (and, as usual, without any scientific evidence) that Asperger's was a real mental illness, and that Recovered Memory Therapy was a real therapeutic method. Fortunately, and to some extent because of these credibility issues, society is in the midst of dumping psychology as a serious endeavor:
In summary, until there is some science in brain research, all this talk about IQ testing is overreliant on effects without any clue about causes -- on descriptions without explanations.
Notice the name of President Obama's recently announced program -- the "Brain Initiative", not the "Mind Initiative". The handwriting is on the wall.
the point is that they predict future performance equally for different groups, not just that they predict performance. your language is alarmingly exaggerated and pompous for someone who lacks basic reading comprehension skills and is entirely ignorant about the subject of intelligence testing.
Quote: "However, IQ tests may well be biased when used in other situations. A 2005 study stated that "differential validity in prediction suggests that the WAIS-R test may contain cultural influences that reduce the validity of the WAIS-R as a measure of cognitive ability for Mexican American students,"[123] indicating a weaker positive correlation relative to sampled white students. Other recent studies have questioned the culture-fairness of IQ tests when used in South Africa.[124][125] Standard intelligence tests, such as the Stanford-Binet, are often inappropriate for children with autism; the alternative of using developmental or adaptive skills measures are relatively poor measures of intelligence in autistic children, and may have resulted in incorrect claims that a majority of children with autism are mentally retarded."
Just one sample from a large literature on this topic.
> your language is alarmingly exaggerated and pompous for someone who lacks basic reading comprehension skills and is entirely ignorant about the subject of intelligence testing.
Nice argument. Do give us more samples of your logically flawed reasoning. The readers of this forum will surely appreciate your credibility sacrifice.
"the mismeasure of man" is a garbage book by the noted fraud and liar steven jay gould. it certainly should not be used as any sort of reference on intelligence testing.
I don't know enough about The Mismeasure of Man to say whether it's correct or not, but Steven Jay Gould is about as eminent a biologist as there has ever been. The allegation that he is a "noted fraud and liar" is a pretty gross mis-estimate his work, and my personal opinion is that a misapprehension at this level makes it very unlikely that you have good reasons for believing what you do. To casual lurkers: what the user "truthteller" has just said is essentially alarmist garbage, and you should regard their claims with skepticism of a pretty high degree.
In the future, note that calling someone a "noted fraud and liar" is a very serious claim, and you should think carefully about who you level it against. It's powerful language, but used against the wrong person, will make you look silly, and not them.
I've seen truthteller's comments before. He should probably be hellbanned but he's flown under the radar for some reason. He's been around for 119 days, has tons of comments and only a comment karma of 37.
You called India a "shit hole". The entire country. Do I have to be an Indian nationalist to not see that kind of a comment as inane? If you had some kind of comment to make about the positive side of British Raj and the crown's denial of Indians right to govern themselves, it probably required maybe a less "shit hole" of a comment.
Quote: "The first edition of The Mismeasure of Man won the non-fiction award from the National Book Critics Circle; the Outstanding Book Award for 1983 from the American Educational Research Association; the Italian translation was awarded the Iglesias prize in 1991; and in 1998, the Modern Library ranked it as the 24th-best non-fiction book of all time.[10] In December 2006, Discover magazine ranked The Mismeasure of Man as the 17th-greatest science book of all time."
the opinions of ignorant journalists are not really relevant. it was strongly criticized by experts in the relevant area. do you realize how intellectually lazy you look when you form strong opinions on subjects without even doing basic research first?
If self-reference were a disease, you would be in an emergency room. You know nothing about me or the research I have conducted, apart from the fact that your argument represents an all-too-common logical error.
> the opinions of ignorant journalists are not really relevant.
> it was strongly criticized by experts in the relevant area.
So, which is it? Did journalists decide, or did experts decide? And do you know why neither of those sources carry weight in science, a field where evidence trumps eminence?
Do you know why I'm playing you along, even though you have nothing to contribute to this discussion? I just want the readers in this forum to see what passes for reasoning among psychologists and their supporters.
at this point you are just embarrassing yourself with your weird crusade attack "psychologists and supporters". I'm sure most readers in this forum feel intuitively that mental ability can be measured with some accuracy, so I doubt you will convince many people. and anyone who cares to look will find a vast psychometric literature that supports the validity of IQ.
I don't need to. The director of the NIMH already agrees with me, and high-level policy changes are under way to permanently change the status of psychiatry and psychology, demote them to the status of astrology. Didn't you get the memo?
> ... anyone who cares to look will find a vast psychometric literature that supports the validity of IQ.
Yes, that works for people suffering from a bad case of confirmation bias, and who can't grasp basic scientific principles. The rest of us will continue practicing science and advocating in favor of neuroscience as psychology's obvious replacement.
IQ testing will become valid only when it is based on science rather than anecdote. Assuming that ever happens.
For anybody reading this in the future, "truthteller" isn't the voice of reason in this thread, he/she is a troll.
The link above by defens is a legitimate criticism of The Mismeasure of Man and is well worth reading. It doesn't speak to the overarching theme of the book, which is it's attack on the goals and the content of intelligence testing, but to a mischaracterization that Gould made of the conclusions of someone else's research, turning them into a bit of a straw man representing subconscious testing bias. It definitely weakens Gould's case in that regard.
> The link above by defens is a legitimate criticism of The Mismeasure of Man and is well worth reading.
I agree completely -- the Gould book was an important contribution to the debate about IQ testing, and it contained a number of errors. Both of the above statements are true -- indeed, it's rare for such an important work of this scope to be error-free.
It's my hope that, as psychology is replaced by neuroscience (a process now under way), the role of opinions will be substantially replaced by scientific evidence, which until now has been in deplorably short supply in this field.
This whole post is a perfect example of the danger of Taleb's work. Someone with no knowledge of finance or statistics has read his books and now feels able to make extremely strong statements about a link between financial theory and financial crises. :(
no, it's just bad writing. meandering nonsense is never good writing, though perhaps it boosts your ego to feel like you are part of a special club (of millions) that understands his ramblings.
could you explain a bit more about the mechanics of buying/selling retail flow? or is there any standard reference for learning more about the details?
We had a contract with a retail brokerage under which we paid them a fixed monthly fee plus a fraction of the flow they sent us in exchange for being their exclusive options market maker. We had to execute the trade at the national best bid and offer (NBBO). We made the difference between the NBBO and whatever we managed to execute at. These are contracts negotiated between broker-dealers, so a relevant attorney would be your best source of information.
Could you go into more detail about the difference between the NBBO and what you were able to execute at?
My understanding is that the NBBO is, by definition, the best executable price. If you're able to execute for a better price then the price you paid was the NBBO.
Most trades will execute at something near but worse than the instantaneous NBBO.
Let's say the market is 147.05 at 148.30 (I, as the market maker, am willing to buy at 147.05 and sell at 148.30). That's the NBBO. If someone IMs me and says they're willing to buy at 147.10, that moved the market and thus the NBBO. I am required, by law, to report that trade to the consolidated tape.
But if someone IMs me and says they're willing to buy at 147, that's worse than the NBBO. I would then consider lifting at 147 and selling at 147.05. Why would someone buy at worse than the market? Maybe the market was 147 when they put in the order and their computers were slow to catch up. Or maybe they're George Soros placing a multi-billion dollar bet and know that if they put an order into the NYSE it's going to execute at much worse than 147. Either way, I functioned as a market maker by taking their problem and making it mine.
Did you mean to say that the person in the second example is a seller? (147 is cheaper for a buyer than 147.05, the NBBO. You "lift" an ask not a bid).
It would be nice to hear from him how often he executed "inside" NBBO. That's easier to do in spread trades than in simple puts and calls.
Also note, he said he was acting as a MARKET MAKER.
E.g. let's look at where a particular AAPL option closed on Friday:
AAPL131221C00550000 9.65 bid 9.85 ask
Another, bigger difference because it's further in the money:
AAPL131221C00500000 54.15 bid 55.20 ask
Another, bigger difference because it's further out in time:
AAPL150117C00550000 bid 65.50 ask 66.40
The market maker buys at bid, sells at ask. If he can do that thousands of times a day in a thousand different securities, the profits start to add up.
Doing this in options means the market maker needs to be quite nimble, even more than with stocks. This is because he's buying or selling a DERIVATIVE and the UNDERLYING security can change in price quite quickly.
But that's why these guys buy fast computers and why they pay smart people the big bucks to write software for those computers (and to e.g. program FPGAs for high speed trading).
Option bid/ask spread is much wider because 1) notional value is 100 shares as opposed to 1 share of stock, 2) has an additional mysterious value, volatility in the option pricing formula, 3) for OTM options, has volatility simile aka "black swan" properties that elevates the pricing and spread higher.
It's not as easy to make money being a options marketmaker because you have to realize not all of your trades will be someone taking your bid/ask. Even so, you'll have delta-hedge your position with the underlying which is a imperfect hedge that is subject to jump risk. Typically a AAPL options marketmaker is taking orders from traders and has up to couple hundred of these AAPL with long name positions, and they have to balance out the greeks, delta and gamma. They may even have to buy some options themselves to hedge themselves and pay the market price.
so the consensus in psychometrics is that iq tests are not systematically biased against particular groups.
and of course it measures a lot more than a person's ability to take intelligence tests". just look at the "social outcomes" section of the wikipedia page...