A recent study surveyed 5,000 British families about their experiences with volunteering and their mental health. Participants completed the same survey every two years from 1996 to 2008.

    About 20 percent of the survey participants reported doing regular unpaid work Researchers found that these volunteers also scored highest on their mental health scores. The two were linked so directly that the more a person volunteered, the happier they were.

    One could argue a chicken-and-egg theory: happier people are more likely to have the time, money, energy and resources to give back to others. But even when researchers adjusted for education, social class and total health, the link was there, suggesting that the mental increase came from volunteering and not the other way around.

    According to Dr. Stephen G. Post, author of The Hidden Gifts of Helping, when you help others, your brain releases feel-good chemicals, which can help cells repair themselves and grow. And this translates to better health.

    So volunteering can help improve both your physical and mental health—on one condition. You have to mean it. People who volunteered for "self-oriental" reasons, either because they were forced to do so for work or school or because they were trying to get away from problems in their lives, had a mortality（死亡率）risk that was similar to those who didn't volunteer at all. It was only when people were volunteering out of a true sense of sympathy that they saw any health benefits.

    So whether it's arranging books at the library or walking dogs at the animal shelter, find a cause that's important to you and give it a try. Volunteering is a good way to develop a sense of connection that not only helps your community, but may also be good for you.

    Hannah Levine decided she wanted to give hugs to all of the children and families in need at local hospitals.

    Because she couldn't give them hugs one by one, Levine, then a sixth-grader, decided she would use her talents(才能) to do the next best thing. She began to knit(编织) hats, scarves, and blankets for families staying at the Ronald McDonald House at Stanford. Her creations also went to Bundle of Joy, a program that provides newborn baby items for families in need, and to Knitting Pals by the Bay, a local organization that provides hand-knitted caps to cancer patients.

    "I love to knit, and I thought it would be a great idea to make all these handmade items for kids and adults who need them. It would be like a hug for them." Levine explained.

    Levine started the project about a year ago. "I think it's just really fun to do, and it keeps me busy." said Levine, now 13.

    Once she got started, Levine realized that her project could be much bigger than the goods she was able to produce with just her own hands. So she sent emails to her school and communities, asking for knitted donations(捐赠物) to the project she named "Hannah's Warm Hugs". She also posted advertisements at Starbucks and other locations in her area. The warm goods began to pour in.

    "It was amazing; more strangers than people she knew started dropping donations at our door." said Levine's mother, Laura Levine. "We ended up with this huge box of items she was donating."

    The knitted items numbered in the hundreds. Levine made her first round of donations around Hanukkah (an eight-day Jewish holiday in November or December) and later received thank-you letters from the organizations. Levine is still knitting, and she said the project will continue.

    "It has turned into a bigger thing than she had thought." her mom said. "It made her feel pretty good; it made us feel pretty good.”

The Domestication （驯化）of Cats

    For centuries, the common view of how domestication had occurred was that prehistoric people, realizing how useful it would be to have animals kept for food, began catching wild animals and breeding （繁殖）them. Over time, by allowing only animals with "tame"（驯养）characteristics to produce their babies, human beings created animals that were less wild and more dependent upon people. Eventually this process led to the domestic farm animals and pets that we know today, having lost their ancient survival skills and natural abilities.

    Recent research suggests that this view of domestication is incomplete. Prehistoric human beings did catch and breed useful wild animals, but specialists in animal behavior now think that domestication was not simply something people did to animals—the animals played an active part in the process. Wolves and wild horses, for example, may have taken the first steps in their own domestication by hanging around human settlements, feeding on people's crops and getting used to human activity. The animals which were not too nervous or fearful to live near people produced their babies that also tolerated humans, making it easier for people to catch and breed them.

    In this version, people succeededin domesticating only animals that had already adapted easily to life around humans. Domestication required an animal that was willing to become domestic. The process was more like a dance with partners than a victory of humans over animals.

    At first glance, the laming of cats seems to fit nicely into this new story of domestication. A traditional theory says that after prehistoric people in Egypt invented agriculture and started farming, rats and mice gathered to feast on their stored grain. Wildcats, in tum, gathered at the same places to hunt and eat the rats and mice. Over time, cats got used to people and people got used to cats. Some studies of wildcats, however, seem to call this theory into question. Wildcats don't share hunting and feeding areas, and they don't live close to people. Experts do not know whether wildcats were partners in their own domestication. They do know that long after people had acquired domestic dogs, sheep and horses, they somehow acquired domestic cats. Gradually they produced animals with increasingly tame qualities.

    Next time you raise an eyebrow at the views of your partner, friend, sibling （兄弟姐妹） or colleague, remember they could be helping to make you smarter. New research shows that intelligence is not fixed but can be improved throughout adulthood by family members, bright mates and intellectually challenging careers. The study challenges the commonly held belief that intelligence is fixed by the age of about 18.

    Scientific consensus suggests that intelligence is controlled by genes, with environmental factors such as schooling and nutrition playing a partial role up to this age. After this point, IQ scores become steady（稳定的）. But James Flynn, professor of political studies and psychology at the University of Otago in New Zealand, argues that people can "upgrade" their own intelligence throughout their lives. He believes intellectual stimulation（刺激）from others is important as the "brain seems to be rather like a muscle - the more you use it, the stronger it gets". However, the opposite is also true - so people sharing a home or workplace with those who are intellectually challenged risk seeing their IQ levels nosedive as a result.

    Professor Flynn analyzed US intelligence tests from the last 65 years and created new IQ "age tables". He found a bright ten-year-old with brothers and sisters of average intelligence will suffer a five to ten point IQ disadvantage compared to a similar child with equally bright brothers and sisters and special educational treatment to help pull them up.

    Professor Flynn also concluded that although genetics and early life experiences determine about 80% of intelligence, the remaining 20% is linked to lifestyle. This means that people can raise their IQ, or allow it to fall, by ten points or more. He suggested the best way to improve IQ levels is to mix with bright friends, find an intellectually challenging job and marry someone cleverer.

    It's school time again! You're probably feeling excited and maybe a little sad for the vacation is over. Some kids feel nervous on the first day of school because of all the new things: new teachers, new friends, and maybe even a new school. Luckily, these "new" worries only stick around for a little while. Let's find out more about going back to school.

    Most teachers kick off the school year by introducing themselves and talking about what you'll be doing that year. Some teachers give students a chance to tell something about themselves to the rest of the class.

    When teachers do the talking on the first day, they often go over classroom rules so you'll know what's allowed and what's not. Pay close attention so you'll know if you need to raise your hand to ask a question and what the rules are about visiting the restroom.

    You might already know a lot of people in your class on the first day. But it's a great day to make new friends, so try to say "hello" to the kids you know and new ones that you don't. Make the first move and you'll be glad about what you did and so will your new friends!

    Most teachers let you pick your own seat on the first day, but by the second or third morning, they'll have mapped out a seating plan. It's a good idea to write down where your seat is in your notebook so you don't forget.

    Here are a few final tips for a fantastic(奇异的) first day: Get enough sleep. Have a healthy breakfast. Try your best. Develop good work habits, like writing down your assignments(作业) and handing in your homework on time. Take your time with schoolwork. If you don't understand something, ask the teacher.