Are we getting more stupid? According to Gerald Crabtree, a scientist at Stanford University in the US, we are.  You may not want to hear this, but Crabtree believes that human intelligence reached its peak more than 2,000 years ago and ever since then has been going downhill. “If an average Greek from 1,000 BC were transported to modern times, he or she would be one of the brightest among us,” Crabtree told The Guardian.

    At the heart of Crabtree's thinking is a simple idea. In the past, intelligence was critical for survival when our ancestors had to avoid dangerous animals and hunt for food. The difference of being smart or stupid is often life or death. However, after the spread of agriculture, when our ancestors began to live in dense ( 稠密的）farming communities, the need to keep their intelligence in peak condition gradually reduced. This is not hard to understand. Most of the time,pressure is what keeps us going – you need the pressure from your teachers to finish your homework; the pressure of looking pretty prompts(促使) you to lose weight when summer comes. And the same is also true of our intelligence – if we think less, we become less smart.

    These mutations(变) are harmful to our intelligence and they were all developed in the past 3,000 years. The other evidence that Crabtree holds is in our genes. He found that among the 2,000 to 5,000 genes that we have that determine human intelligence , there are two or more mutations in each of us. However, Crabtree's theory has been criticized by some who say that early humans may have better hunting and surviving abilities, but people today have developed a more diverse intelligence. For example, spearing a tiger doesn't necessarily require more brainpower than playing chess or writing a poem. Moreover, the power of modern education means a lot more people have the opportunity to learn nowadays. “You wouldn't get Stephen Hawking 2,000 years ago. He just wouldn't exist,” Thomas Hills of the University of Warwick, UK, told Live Science. “But now we have people of his intellectual capacity doing things and making insights(洞察力) that we would never have achieved in our environment of evolutionary adaptation.”

    Last summer, two nineteenth-century cottages were rescued from remote farm fields in Montana, to be moved to an Art Deco building in San Francisco. The houses were made of wood. These cottages once housed early settlers as they worked the dry Montana soil; now they hold Twitter engineers.

    The cottages could be an example of the industry' s odd love affair with “low technology,” a concept associated with the natural world, and with old-school craftsmanship (手艺) that exists long before the Internet era. Low technology is not virtual (虚拟的) —so, to take advantage of it, Internet companies have had to get creative. The rescued wood cottages, fitted by hand in the late eighteen-hundreds, are an obvious example, but Twitter's designs lie on the extreme end. Other companies are using a broader interpretation (阐释) of low technology that focuses on nature.

    Amazon is building three glass spheres filled with trees, so that employees can “work and socialize in a more natural, park-like setting.” At Google's office, an entire floor is carpeted in glass. Facebook's second Menlo Park campus will have a rooftop park with a walking trail.

    Olle Lundberg, the founder of Lundberg Design, has worked with many tech companies over the years. “We have lost the connection to the maker in our lives, and our tech engineers are the ones who feel impoverished (贫乏的) , because they're surrounded by the digital world,” he says. “They're looking for a way to regain their individual identity, and we've found that introducing real crafts is one way to do that.”

    This craft based theory is rooted in history, William Morris, the English artist and writer, turned back to pre-industrial arts in the eighteen-sixties, just after the Industrial Revolution. The Arts and Crafts movement defined itself against machines. “Without creative human occupation, people became disconnected from life,” Morris said.

    Research has shown that natural environments can restore(恢复) our mental capacities. In Japan, patients are encouraged to “forest-bathe,” taking walks through woods to lower their blood pressure.

    These health benefits apply to the workplace as well. Rachel Kaplvin, a professor of environmental psychology, has spent years researching the restorative effects of natural environment. Her research found that workers with access to nature at the office—even simple views of trees and flowers—felt their jobs were less stressful and more satisfying. If low-tech offices can potentially nourish the brains and improve the mental health of employees then, fine, bring on the cottages.

    The ninth week of SEAL(Sea, Air, Land) training is referred to as Hell Week. It is six days of no sleep, physical and mental suffering and one special day at the Mud Flats (泥沼）where you will sink into the mud.

    It is on Wednesday of Hell Week that we came down to the mud flats and spend the next 15 hours trying to survive the freezing-cold mud, the cold wind and the strong pressure from the instructors to give up.

    As the sun began to set that Wednesday evening, my training class, having broken some of the rules, was ordered into the mud. We sank into the mud until only our heads could be seen. The instructors told us we could leave the mud if only five men would give up—just five men and we could get out of the cold.

    Looking around the mud flat, it was clear that some of us were about to give up. It was still over eight hours till the sun came up--eight more hours of coldness. Our cries were so loud that it was hard to hear anything. And then, one voice began to fly through the night--one voice raised in song.

    The song sounded terrible, but it was sung with great power. One voice became two, and two became three, and before long everyone in the class was singing.

    We knew that if one man could rise above the suffering then others could as well. The instructors warned us of more time in the mud if we kept up the singing—but the singing went on and on. And somehow, the mud seemed a little warmer, the wind a little weaker and the morning not so far away.

    If I have learned anything in my time traveling the world, it is the power of hope. The power can change the world by giving people hope.

    So, if you want to change the world, start singing when you're up to your neck in mud.

    Minecraft, a video game with which you can build virtual（虚拟的） worlds, will be used in the classroom. Microsoft bought the game from its Swedish creator for 2.5 billion dollars. Now, the software（软件） company wants to offer schools a special educational version（版本）.

    MinecraftEdu is an add-on to the game, which has specially created by teachers for classroom use. While thousands of classes around the world are already using Minecraft in their lessons, Microsoft wants to make it easier for schools to use the software.

    Minecraft is a game that can be used in many subjects, including maths, science and geography. Microsoft wants to add new features to the educational version, for example letting students take photos and putting them into an online diary. The new version will allow children to download the game and at home without having to pay more money for it. Microsoft is expected to ask students and teachers for about 5 dollars a year to use the game in school and at home.

    According to Microsoft, Minecraft has 100 million players around the world. It has become one of the best-selling games of all times. Pupils can create their own virtual worlds with the help of special building blocks. Joy Morsi, a New York high school teacher, says that Minecraft helps develop the imagination of children in the classroom. Besides, teachers around the world create new things and share them with others, so that the Minecraft community keeps growing.

    Microsoft plans to make the game of available to pupils and students of all ages, from primary school through to college. the company plans to add Minecraft to an Office 365 account(账户), so that it can also sell more of its Office software.

    Bill Bowerman was a track coach. He wanted to help athletes run faster. So he had learned how to make running shoes. He had also started a shoe company with a friend. It was 1971. Running shoes at the time were heavy. They had spikes (鞋钉) on the sole (鞋底). The spikes tore up the track and slowed down runners.

    To make a lighter shoe, Bill tried the skins of fish. To make a better sole, he wanted to replace the spikes. Bill dug through his wife Barbara's jewelry box. He hoped to find a piece of jewelry with an interesting pattern. He would then copy the pattern onto the new soles. Nothing worked. Bill was defeated.

    Then, one Sunday morning, Barbara made Bill waffles (华夫饼) for breakfast. Bill watched her cook.

    He studied the criss-cross pattern on a waffle iron.

    Inspiration struck. The pattern on the waffle iron was just what Bill was looking for. The squares were flatter and wider than sharp spikes. The pattern would help the shoes hold any surface without tearing into it.

When Barbara left the house, Bill ran to his lab. He took the liquid chemicals that, when mixed, would harden into the sole of a shoe. He poured the mixture into the waffle iron—and the Waffle Trainer was born.

Bill's company put the Waffle Trainer on market in 1974. It was a huge hit. Maybe you've heard of that company—it's called Nike. And today it's worth around $100 billion.

It was the waffle iron that had changed the course of Bill's life—and helped turn Nike into a well-known name. Today, the waffle iron is kept at Nike headquarters. It serves as a reminder that if we keep trying, we can find a solution to even the most difficult problems. And those solutions can come from unlikely places, even the breakfast table.

When Lamont Thomas, a retired restaurant employee, became an empty-nester, it was the end of a parenting story. A couple years ago, the divorced father of two became a hero when he took on a kid named Michael Perez in 2001.

"He was a good young man and I just hated to see him in the welfare system," Thomas said.

Thomas eventually adopted Perez, who now works as a nurse.

Perez was just the beginning. Over the next 15 years, Thomas raised more than 30 kids. He did so all as a single parent and with all of his heart.

"Every child that I have had, it was my goal to make a difference in their lives," he said.

When he retired from raising children to spend time fishing and traveling, that didn't last for long.

"It really was a shocker," Perez said. "I didn't expect for him to restart and to do it all over again. "

Thomas began to foster again when he found out that five brothers and sisters all under the age of 6 were going to be permanently broken up. To guarantee they stayed a family, he adopted all of them too.

"I had to help them. They deserved to be raised together," Thomas said.

After Thomas' story first aired, CBS News received a lot of surprising mail from women who expressed interest in the great man. Some notes weren't obvious, others were braver, "Ask Mr. Thomas if he would like a pen pal," wrote one woman, while another said, "I'll marry Lamont!"

But the kids see no room for romance, nor does Thomas.

"I was about to change my phone number," he said.

So he remains single. He spent Thanksgiving with family and is more grateful than ever.