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People Getting Dumber? Human Intelligence Has Declined Since Victorian Era, Research Suggests

Posted by on May. 23, 2013 at 6:26 AM
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2 moms liked this

People Getting Dumber? Human Intelligence Has Declined Since Victorian Era, Research Suggests

The Huffington Post  |  By Posted:   |  Updated: 05/22/2013 10:59 pm EDT

Our technology may be getting smarter, but a provocative new study suggests human intelligence is on the decline. In fact, it indicates that Westerners have lost 14 I.Q. points on average since the Victorian Era.

What exactly explains this decline? Study co-author Dr. Jan te Nijenhuis, professor of work and organizational psychology at the University of Amsterdam, points to the fact that women of high intelligence tend to have fewer children than do women of lower intelligence. This negative association between I.Q. and fertility has been demonstrated time and again in research over the last century.

But this isn't the first evidence of a possible decline in human intelligence.

"The reduction in human intelligence (if there is any reduction) would have begun at the time that genetic selection became more relaxed," Dr. Gerald Crabtree, professor of pathology and developmental biology at Stanford University, told The Huffington Post in an email. "I projected this occurred as our ancestors began to live in more supportive high density societies (cities) and had access to a steady supply of food. Both of these might have resulted from the invention of agriculture, which occurred about 5,000 to 12,000 years ago."

As for Dr. te Nijenhuis and colleagues, they analyzed the results of 14 intelligence studies conducted between 1884 to 2004, including one by Sir Francis Galton, an English anthropologist and a cousin of Charles Darwin. Each study gauged participants' so-called visual reaction times -- how long it took them to press a button in response to seeing a stimulus. Reaction time reflects a person's mental processing speed, and so is considered an indication of general intelligence.

intelligence declineHipp chronoscope, a device used to measure short intervals of time with an accuracy of 1/1,000th of a second. Hipp chronoscopes were used to measure reaction time in experimental psychology labs in the late 19th Century.

In the late 19th Century, visual reaction times averaged around 194 milliseconds, the analysis showed. In 2004 that time had grown to 275 milliseconds. Even though the machine gauging reaction time in the late 19th Century was less sophisticated than that used in recent years, Dr. te Nijenhuis told The Huffington Post that the old data is directly comparable to modern data.

Other research has suggested an apparent rise in I.Q. scores since the 1940s, a phenomenon known as the Flynn Effect. But Dr. te Nijenhuis suggested the Flynn Effect reflects the influence of environmental factors -- such as better education, hygiene and nutrition -- and may mask the true decline in genetically inherited intelligence in the Western world.

This new research was published in the April 13 issue of Intelligence.

http://www.huffingtonpost.com/2013/05/22/people-getting-dumber-human-intelligence-victoria-era_n_3293846.html?utm_hp_ref=mostpopular

by on May. 23, 2013 at 6:26 AM
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lokilover
by Bronze Member on May. 23, 2013 at 6:45 AM

I don't treat these kind of studies that seriously. There is a well-known effect know in IQ studies called the Flynn Effect, which shows that the average IQ has been rising. That would be an example that shows the opposite trend.

I don't think humans are any more or less intelligent than they were before.

teri4lance
by Silver Member on May. 23, 2013 at 6:46 AM
9 moms liked this
I think a lot of it is bc we keep passing laws to protect the idiots from their own stupidity.
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futureshock
by Ruby Member on May. 23, 2013 at 2:27 PM


Quoting teri4lance:

I think a lot of it is bc we keep passing laws to protect the idiots from their own stupidity.

lol

futureshock
by Ruby Member on May. 23, 2013 at 2:28 PM
1 mom liked this


Quoting lokilover:

I don't treat these kind of studies that seriously. There is a well-known effect know in IQ studies called the Flynn Effect, which shows that the average IQ has been rising. That would be an example that shows the opposite trend.

I don't think humans are any more or less intelligent than they were before.

You do realize that the Flynn Effect was discussed in this article, right?

Other research has suggested an apparent rise in I.Q. scores since the 1940s, a phenomenon known as the Flynn Effect. But Dr. te Nijenhuis suggested the Flynn Effect reflects the influence of environmental factors -- such as better education, hygiene and nutrition -- and may mask the true decline in genetically inherited intelligence in the Western world.

futureshock
by Ruby Member on May. 23, 2013 at 2:29 PM
1 mom liked this

This part is indisputable:

women of high intelligence tend to have fewer children

What exactly explains this decline? Study co-author Dr. Jan te Nijenhuis, professor of work and organizational psychology at the University of Amsterdam, points to the fact that women of high intelligence tend to have fewer children than do women of lower intelligence. This negative association between I.Q. and fertility has been demonstrated time and again in research over the last century.

Clairwil
by Ruby Member on May. 23, 2013 at 3:17 PM

If you want a factor that could affect things, in the long term: Caesarean Sections

They allow babies with larger heads to survive.  There's a positive correlation of about 0.3 between size of brain, and IQ test score.

kailu1835
by Ruby Member on May. 23, 2013 at 3:19 PM
9 moms liked this
You can thank technology for that. The more technologically advanced we become, the less intelligent our brains get, because they don't need to be worked as hard.
Clairwil
by Ruby Member on May. 23, 2013 at 3:21 PM
Quoting futureshock:

This part is indisputable:

 women of high intelligence tend to have fewer children than do women of lower intelligence. This negative association between I.Q. and fertility has been demonstrated time and again in research over the last century.

However this is partially compensated by the chances of their children having grandchildren.   For every 16 more points of IQ, a man is 35% more likely to find a wife, rather than remain single all his life.


Clairwil
by Ruby Member on May. 23, 2013 at 3:22 PM
3 moms liked this
Quoting kailu1835:

You can thank technology for that. The more technologically advanced we become, the less intelligent our brains get, because they don't need to be worked as hard.

Evidence?


Mommy2BeAmy
by Silver Member on May. 23, 2013 at 3:22 PM
Thats why they on a verge of finding a cure for hiv
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