Why Sisters Are Scientifically Better Than Brothers (and Other Important Discoveries)

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If you're keeping tabs on the score between robots and humans, you've probably heard about the robot named Adam who made a scientific discovery back in April without any human assistance. Well, sort of. He made the discovery after some human scientists gave him a specific project to work on. And while the event was chalked up as a win in the artificial intelligence column, we're here to tell you that Adam's still got a lot of catching up to do before he's doing the work of real human scientists. Need proof? From definitive proof on why sisters are better than brothers to the reasons we itch and scratch, here's our monthly round-up of (human!) scientific discoveries you ought to know about.

Science Proves Sisters are Way Better than Brothers?!

New research from the University of Ulster confirms that girls are made of sugar and spice and everything nice. Tony Cassidy, the lead researcher on the project, found sisters make their siblings more optimistic and help families deal with problems in emotionally healthy ways. Families with at least one sister are more cohesive and communicate more often. Girls who grow up with a sister are more independent and achieve more than girls who have brothers. Cassidy surveyed 571 young adults between 17 and 25. He found that sisters have the most positive impact on broken families. Only children scored in the mid-range for happiness while boys who had only brothers were the least happy.

Tony Cassidy, University of Ulster; presentation at the British Psychological Association Annual Conference.

Reducing Autism Cases by 15%

There's good news in the fight against autism: Hakon Hakonarson's new research may drastically reduce the number of autism cases in the world. Hakonarson, a scientist at the University of Pennsylvania, has been running the largest and most exhaustive genetic study on the disorder. He's analyzed DNA from 2,600 autistic children, 2,000 of their family members, and 7,000 healthy controls. Hakonarson's team has found several variations in chromosomes, but one of the most important might be the variation on gene CDH10, which was found in 65 percent of autistic participants. Amazingly, researchers hypothesize that by fixing this variation they could reduce the number of autism cases by 15 percent. They also found that autism was linked strongly to 30 genes, which produce proteins that help brain cells migrate to the correct location and connect to neighboring cells. While it will be years before autism is completely understood, Hakonarson's results have given scientists a foothold since they can now point to 133 genes which directly contribute to the disorder.

Hakon Hakonarson, et al. "Common genetic variants on 5p14.1 associate with autism spectrum disorders," Nature.

Poverty Can Affect Your Memory

Social scientists have long understood that poorer children don't perform as well as their more affluent peers. Researchers know that inadequate schools, infrequent access to health care, and low quality diets contribute to lower academic and career achievement—the so-called income-achievement gap. But two child development experts have also found that the stress of poverty changes brain functioning. Cornell University's Gary Evans and Michelle Schamberg studied 195 poor and middle class Caucasian students. By measuring their stress hormones and blood pressure at age 9 and 13, the researchers found a direct link between poverty and stress. The duo also tested 17-year old students on their memory-- a reliable indicator of reading, language and problem-solving abilities. Children who grew up in poverty recalled 8.5 items while children who were more affluent remembered 9.44 items. The duo theorizes that stress hormones damage grey matter leading to the deficiencies in working memory.

Gary W. Evans and Michelle A. Schamberg "Childhood poverty, chronic stress, and adult working memory," Proceedings of the National Academy of Sciences.

The Science of Scratching

itching-powder.jpgThe next time you complain about your itchy back and feet, remember that you don't have it that bad. In one of the more disturbing accounts we've ever read (if you're squeamish, don't read ahead), a June 2008 New Yorker article by author Atul Gawande introduced the world to M, a woman who had recently suffered from shingles. M, who is also HIV positive, could not stop scratching the right side of her head. She complained to her doctor who prescribed the normal anti-itching remedies, but the feeling wouldn't cease. Her doctor suggested it was a form of OCD, yet OCD medications didn't quell the itch either. Worse still, the condition got so bad that M actually scratched through her skull.

For people suffering from serious itching conditions, scratching does little to stop the sensation. But now, thanks to Glenn Giesler Jr. and Steve Davidson's recent study, we might understand what's going on when you need to itch. Here's how it works: When a mosquito bites your arm, your sensory neurons respond to the histamine by carrying the itch message through the spinal cord to the thalamus in the brain. The thalamus passes the itch message to the cerebral cortex, which produces the itching sensation at the bite. That's what makes you want to scratch the bite. But Giesler and Davidson did something clever. By using primates, Giesler applied histamine to the animals' feet. If the researchers itched the foot after applying the histamine, the message was disrupted in the spinal cord, meaning the brain didn't get the order to create the itching feeling. The hope is that by understanding how scratching and itching works, it will allow researchers to find better solutions soon.

Steve Davidson, Xijing Zhang, Sergey G Khasabov, Donald A Simone and Glenn J Giesler Jr. "Relief of itch by scratching: state-dependent inhibition of primate spinothalamic tract neurons," Nature Neuroscience.

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June 4, 2009 - 4:15am
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