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Author Topic: USA Intelligence Falling, and an Undiscovered Neurotoxin?  (Read 1372 times)

Offline Jimbee

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I don't have the cite. But I assume everyone knows that intelligence tests in the USA show that the people of the United States are of lower IQ than they were just a hundred years ago.

My question is Why? And also, could there be some undiscovered neurotoxin responsible?

There are many additives, to our food, our environment. And we still don't fully know the effect of all of them.

Could I be on to something with this?



Offline evan_au

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Re: USA Intelligence Falling, and an Undiscovered Neurotoxin?
« Reply #1 on: 27/08/2014 03:35:45 »
It is called the Flynn Effect, and it suggests that average IQ scores have increased during the past century.

However, the effect has levelled out in the past 20 years, and is in decline in some countries, although the reasons are a source of debate.

Offline alancalverd

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Re: USA Intelligence Falling, and an Undiscovered Neurotoxin?
« Reply #2 on: 27/08/2014 11:29:53 »
IQ tests measure the ability to do IQ tests. As they became more popular, kids got more practice at them and so the scores increased. But at some point it was realised that many IQ tests were based on cultural presumptions. This had two effects: to reduce the popularity of IQ testing, and to flatten the curve of "delta IQ" as society became more homogeneous. With less exposure and practice, it is quite likely that the average performance has declined.

You can also look at sample stratification. A hundred years ago it is quite likely that nobody tested US blacks or Hispanics because most of them didn't feature in mainstream education and the few that did, were extremely bright, thus pushing up the apparent average. Improved and enlightened social conditions, including compulsory education for all, means that those who were previously excluded from testing are now included, including therefore the 50% who by definition are below the true average, thus depressing the apparent average.   

A hundred years ago, many UK army recruits were rejected because they had tuberculosis. With improved living conditions this is no longer a serious feature, but as compulsory sport and milk have been eradicated from the school curriculum and it has been deemed unsafe for kids to walk anywhere or play outside, increasing numbers are rejected on the grounds of insufficient bone density: according to one medical officer I met, "Some break their legs just marching across the parade ground. There's no way they can jump out of aeroplanes and be fit to fight." It is equally possible that the abandonment of rote learning and formality in education has led to a reduction in the ability to pass IQ tests. We now have a population that can express their individuality and fight synthesised aliens on a computer screen, but can't march or follow orders.   
« Last Edit: 27/08/2014 16:01:29 by alancalverd »

The Naked Scientists Forum

Re: USA Intelligence Falling, and an Undiscovered Neurotoxin?
« Reply #2 on: 27/08/2014 11:29:53 »


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