evolution

Well, at least about dating, according to Dan Slater’s recent opinion piece in the New York Times.  Charles Darwin, who is famous for his theories of evolution, argued that through competition for mates, natural selection encouraged man’s “more inventive genius” while nurturing women’s “greater tenderness.”  So, he suggested that the gender roles he saw in Victorian England—men making money and women staying home—dated back centuries.

Decades later, social scientists applied Darwin’s theories to ideas about mating and concluded that men are less selective about whom they’ll sleep with, men like casual sex more than women, and men have more sexual partners over a lifetime.  These assumptions persist today, and many evolutionary psychologists have studied them and argued in their favor.  For example,

  In 1972, Robert L. Trivers, a graduate student at Harvard…argued that women are more selective about whom they mate with because they’re biologically obliged to invest more in offspring. Given the relative paucity of ova and plenitude of sperm, as well as the unequal feeding duties that fall to women, men invest less in children. Therefore, men should be expected to be less discriminating and more aggressive in competing for females.

Critics of this theory (and many other evolution-based theories) argue that cultural norms, not evolution, impact human behavior.  This argument is quite sociological, though it has also found support in the work of psychologists.

Take the question of promiscuity. Everyone has always assumed — and early research had shown — that women desired fewer sexual partners over a lifetime than men. But in 2003, two behavioral psychologists, Michele G. Alexander and Terri D. Fisher, published the results of a study that used a “bogus pipeline” — a fake lie detector. When asked about actual sexual partners, rather than just theoretical desires, the participants who were not attached to the fake lie detector displayed typical gender differences. Men reported having had more sexual partners than women. But when participants believed that lies about their sexual history would be revealed by the fake lie detector, gender differences in reported sexual partners vanished. In fact, women reported slightly more sexual partners (a mean of 4.4) than did men (a mean of 4.0).

A more recent study challenged the idea that women are more selective.  In speed dating, the social norm instructs that women sit in one place while men rotate tables.  In 2009, Psychologists Eli J. Finkel and Paul W. Eastwick conducted an experiment in which the men remained seated and the women rotated.  By switching the role of the “rotator,” they found that women became less selective while men appeared more selective.

Slater’s opinion piece, found here, cites several other studies that cast doubt on the notion that evolution dictates gendered behavior.  But, that doesn’t mean that Darwinians are backing down. The debate will likely continue, but Slater gives the last words to those who challenge Darwinian ideas:

“Some sexual features are deeply rooted in evolutionary heritage, such as the sex response and how quickly it takes men and women to become aroused,” said Paul Eastwick, a co-author of the speed-dating study. “However, if you’re looking at features such as how men and women regulate themselves in society to achieve specific goals, I believe those features are unlikely to have evolved sex differences. I consider myself an evolutionary psychologist. But many evolutionary psychologists don’t think this way. They think these features are getting shaped and honed by natural selection all the time.” How far does Darwin go in explaining human behavior?

While it’s still hotly debated whether obesity is, in fact, a health crisis, in today’s New York Times, one-time food critic Frank Bruni considers recent obesity research in evolutionary science, medicine, public health, and beyond, concluding that it will require society-level change if we are to stem “a near inevitable tide.” (See also his blog post from today, “The Girth of the Globe,” which discusses Bruni’s perceptions of American dietary habits in a larger context.) The Centers for Disease Control, Bruni writes, now considers about two-thirds of Americans overweight or obese, but “Our current circumstances and our current circumferences may in fact be a toxically perfect fit.”

This is to say, learning to perfect agriculture in abundance has created “plump savings accounts of excess energy” in both our grain silos and our love handles “for an imagined future shortage that, in America today, doesn’t come.” Bruni interviews John Hoffman, an executive producer on HBO’s forthcoming documentary series “The Weight of the Nation,” who tells him that “We’ve only known a world of plenty for maybe 100 years. Our biological systems haven’t adapted to it.” And quoting from Michael L. Power and Jay Schulkin’s book The Evolution of Obesity, Bruni adds, “We evolved on the savannahs of Africa. We now live in Candyland.”

Bruni goes on in his op-ed to consider how one problem in fighting obesity is that we must eat:

“When it comes to smoking or drinking, people generally have to go cold turkey,” notes David Altshuler, an endocrinologist and geneticist, in the documentary. “But fundamentally, we have to eat.” Every meal is a… feat of calibration. “We underestimate how hard it is to change your behavior not once—not for a week or a month until you’re cured—but to change it every day for the rest of your life,” says Altshuler.

In conclusion, Bruni writes we must understand this paradox, cease to vilify the obese, and “rethink and remake our environment much more thoroughly than we seem poised to do.” This may, perhaps, be true well beyond Americans’ own equators.

The ever-expanding world of Google has opened the door for all kinds of large-scale statistical analyses, and in a paper published in Science, physicists Alexander Petersen, Joel Tenenbaum, and their co-authors demonstrate the utility of all that data. They mined through Google’s massive collection of scanned books to discover patterns behind the life and death of words.

The Wall Street Journal picked up on the physicists’ study and recently ran an article on their language evolution findings. For starters, the study makes the most accurate estimation yet of words in the English language—a whopping 1 million, much higher than previous dictionaries have ever recorded (Webster’s Third New International Dictionary has 348,000). And, even though it seems like slang outpaces even dedicated text-decryptors, it appears the English language is growing more slowly than in past decades, partly because the language has already grown so rich there isn’t much use for new words. The words that are born, though, get relatively high frequency of use since they are usually created to describe something new (think “Facebook”).

According to the authors, the world of words is “an inherently competitive, evolutionary environment. All these different words are battling it out against synonyms, variant spellings, and related words.” According to Tenenbaum, the WSJ reports, synonyms seem to be stuck in “Darwinian battles.”

In examples related by the WSJ, the authors document how “Roentgenogram” was the most popular term for “X-ray” (or “radiogram,” another contender) in the 20th century, but is now effectively dead (that is, it’s extremely rare). Similarly, the article cites that “loanmoneys” died circa 1950, killed off by “loans,” and “persistency” is breathing its last, out-competed, appropriately enough, by “persistence.”

Homogenization, the WSJ relates, may be another reason for faster word death rates in the modern era. For instance, William Clark (of Lewis & Clark fame) “spelled ‘Sioux’ 27 different ways in his journals (‘Sieoux,’ ‘Seaux,’ ‘Souixx,’ etc.), and several of those variants would have made it into 19th-century books.” Now, between auto-correct and copy editors, such “chaotic variety” is weeded out much more quickly, essentially speeding up natural selection in the warring world of words.

Furthermore, the study suggests a “tipping point” for words. At around 30 to 50 years old, new words either become long-standing staples of the language of fall out of style like so many Zubaz. The authors suggest this may be because that stretch of decades marks the point when dictionary makers approve or disapprove new candidates for inclusion. Or perhaps it’s generational turnover: ever-innovative children accept or reject their parents’ coinages and the words they leave behind don’t make it to the next generation of speakers.

A common evolutionary theory of religion views the brain as composed of modules and explains religion by a module for supernatural beings.  But, as The Guardian reports, Robert Bellah’s new book takes evolution seriously while challenging this common view as showing a lack of insight into religion as it’s actually lived.

Go back deep into evolutionary time, long before hominids, Bellah invites his readers, because here can be found the basic capacity required for religion to emerge. It is mimesis or imitative action, when animals communicate their intentions, often sexual or aggressive, by standard behaviours. Often such signals seem to be genetically determined, though some animals, like mammals, are freer and more creative. It can then be called play, meant in a straightforward sense of “not work,” work being activity that is necessary for survival.

Such liberated play was found among creatures that didn’t need to work all of the time to survive, and the evolutionary changes that occurred during it weren’t driven by survival pressures.

Mimesis and play are integral pieces of this story of religion because they are precursors to ritual.

…that embodied way of being in the world that enacts, not thinks, understanding. If you have ever played peekaboo with a child, you were together learning about presence and absence. At a more sophisticated level, religions nurture the complex gestures of ritual and practice. Christians perform liturgies, Muslims prostrate themselves in prayer, Buddhists focus attention on breathing. This is the bread and butter of religion. Man can embody truth, reflected WB Yeats, when he cannot rationally know it.

Theoretical exploration and theological propositions accompany the ritual, but they are less fundamental modes of religious understanding.  Indeed, when Plato used the word “theoria,” he was referring to a ritual practice to make a journey to witness a life-changing event rather than theory.