NBC News reports on a theory that humans may be losing intelligence. From the story:
Humans may be gradually losing intelligence, according to a new study.Well, I suppose that if you work for a university, living off a government grant or some fat endowment, it might not take a great deal of intelligence to continue living.
The study, published Monday in the journal Trends in Genetics, argues that humans lost the evolutionary pressure to be smart once we started living in dense agricultural settlements several thousand years ago.
"The development of our intellectual abilities and the optimization of thousands of intelligence genes probably occurred in relatively non-verbal, dispersed groups of peoples (living) before our ancestors emerged from Africa," said study author Gerald Crabtree, a researcher at Stanford University, in a statement.
. . . Early humans lived or died by their spatial abilities, such as quickly making a shelter or spearing a saber-toothed tiger. Nowadays, though almost everyone has the spatial ability to do ostensibly simple tasks like washing dishes or mowing the lawn, such tasks actually require a lot of brainpower, the researchers note.
And we can thank our ancestors and the highly tuned mechanism of natural selection for such abilities. Meanwhile, the ability to play chess or compose poetry likely evolved as collateral effects.
But after the spread of agriculture, when our ancestors began to live in dense farming communities, the intense need to keep those genes in peak condition gradually waned.
And its unlikely that the evolutionary advantage of intelligence is greater than it was during our hunter-gatherer past, the paper argues.
"A hunter-gatherer who did not correctly conceive a solution to providing food or shelter probably died, along with his/her progeny, whereas a modern Wall Street executive that made a similar conceptual mistake would receive a substantial bonus and be a more attractive mate. Clearly, extreme selection is a thing of the past," the researchers write in the journal article.
The hypothesis is counterintuitive at first. After all, across the world the average IQ has increased dramatically over the last 100 years, a phenomenon known as the Flynn Effect. But most of that jump probably resulted from better prenatal care, better nutrition and reduced exposure to brain-stunting chemicals such as lead, Crabtree argues.
This is the epitome of bad science. First, it is an easily tested hypothesis, which the "researcher" apparently didn't do. That is, you could test the hypothesis by using a sample of people from cultures that are or, within the past several generations, were hunter gatherers and test their intelligence against a group that has been civilized for a long period of time; for instance, Australian aborigines or Amazon tribesmen (arguably among the most recent to engage in a hunting/gathering lifestyle) versus Chinese or Indians (arguably among some of the longest stable civilizations in the world). If correct, the current or recent hunter-gatherers should be more intelligent than the long-civilized Chinese or Indians.
Second, there is no justification for the implied hypothesis--i.e., that it doesn't require spatial thinking or intelligence to exist in a civilized culture--that is, it doesn't take any spatial thinking or intelligence to use complicated tools, interact with large groups of people using complicated social rules, build structures, plant and harvest crops, drive vehicles, use writing or numbers, etc. Again, life may be easy and require little intelligence if you are a Standford researcher, but most of us living in the real world have to use our brains.
Third, as noted in the article, IQ apparently is increasing. In other words, there is evidence that contradicts the hypothesis.
Fourth, the political reference undermines the credibility of the entire hypothesis, suggesting that the researcher has probably fallen back on the liberal-progressive theories of the 19th Century, such as the debunked "noble savage" view of pre-literate societies.