Young voters may pick a party for life.
Ten years ago, the World Trade Center attacks rattled political attitudes nationwide. New research shows that blue-to-red shifts took lasting hold of voters who turned 18 in the immediate aftermath.
Researchers at the University of Warwick examined the political affiliations of a group of California voters who registered around their 18th birthdays in 2001. Those whose birthdays were right after September 11 were two percentage points more likely to register as Republicans than peers born just weeks before. Strikingly, those party affiliations persisted in the 2008 elections, where the gap was apparent even for those who had moved and reregistered.
It seems that the post-9/11 surge in support for George W. Bush (thanks to his emphasis on homeland security and the war on terror) led new voters to favor the GOP, and cognitive and social factors helped those affiliations endure, says researcher Ethan Kaplan. "The confirmatory bias says that after I decide I'm a Republican, I then filter information from the world to confirm my views," he says. Another explanation: Individuals develop a political identity and then surround themselves with like-minded peers who bolster their beliefs. The results suggest there's a critical period for winning over young voters—party strategists, take note. —Casey Gueren
Autistic brains share a common defect.
Finding biological markers for autism, a complex disease with both genetic and environmental roots, has been a long-standing challenge. Now, UCLA researchers have discovered a molecular pattern shared by the majority of autistic brains.
The team, led by neurologist Daniel Geschwind, examined postmortem brain tissue from 19 autistic patients and 19 controls. They looked at gene expression in the frontal and temporal lobes, two areas associated with judgment and language. In the healthy brains, more than 500 genes were expressed differently in the frontal vs. temporal lobe. But in 60 to 75 percent of the autistic brains, those differences disappeared—the two lobes looked nearly identical.
The lack of differentiation may underlie abnormal functioning. "If the cerebral cortex is not patterned properly," says Geschwind, "the connections that should form don't form." The next step is to find out if this pattern of gene expression is found in other brain areas. Another mystery is whether these differences are a cause or an effect of the disease.
It's not currently possible to translate these differences in gene expression to specific symptoms or behaviors associated with autism, says Geschwind. But the discovery of shared pathology at the molecular level raises the possibility of one day treating autism with drugs that boost weakened connections in the brain. —Rose Pastore
Culture may actually shape genes.
East Asians' collectivism may be encoded in their genes. Joan Chiao, a cultural neuroscientist at Northwestern University, noticed a 2003 study showing that carriers of a short allele in the serotonin transporter gene are more prone to depression than their long-alleled peers. But the finding raised a conundrum: While Caucasians are equally likely to carry the short or long allele, about 80 percent of East Asians carry the short one, without any apparent ill effects. Why would they have selected for the "bad" allele?
The 2003 study looked only at white New Zealanders, so Chiao broadened the pool to 29 countries and noticed that nations where the short allele flourished (e.g., Japan and China) were twice as likely to be collectivistic than individualistic. Chiao had a hunch that the short allele might confer protection from contagious pathogens; she mapped out her data and saw that in countries where infectious diseases historically ran rampant, collectivism—and the short allele—prevail.
"It's natural selection," Chiao suggests. She believes the short allele boosted fitness in regions teeming with diseases—carriers were less likely to stray from the pack and catch something. In contrast, in low-pathogen regions of the West, successful people tend to be leaders and standouts, so the short allele isn't selected for (and may even be associated with negative outcomes, as the 2003 study suggests).
Now Chiao is examining the reverse situation: Up to 70 percent of all South Africans carry the long allele. Does that make it a country of leaders or anxious loners? It's becoming clear that culture isn't a product of nurture alone; traits are coded into our genes, evolving in response to the environment —Sujata Gupta