2 . Talking to yourself may seem a little shameful. If you’ve ever been overheard criticizing yourself for a foolish mistake or practicing a tricky speech ahead of time, you’ll have felt the social ban against communicating with yourself in words.

    1     Talking to ourselves, whether out loud or silently in our heads, is a valuable tool for thought. Self-talk allows us to plan what we are going to do, manage our activities, regulate our emotions and even create a narrative (叙述)of our experience.

Take a trip to any preschool and watch a small child playing with her toys. You are very likely to hear her talking to herself: offering herself directions and giving voice to her frustrations (沮丧).     2    We do a lot of it when we are young—perhaps one reason for our shyness about continuing with it as adults.                                                                                                                                                                                  

As children, according to a Russian psychologist, we use private speech to regulate our actions in the same way that we use public speech to control the behavior of others.     3    

We internalize (内化) the private speech we use as children—but we never entirely put away the out-loud version.     4     You’re bound to see an athlete or two encouraging themselves with a tart (刻薄的) phrase or scolding (责骂) themselves after a bad shot.

    5     The to-and-fro between different points of view means our thoughts can end up in expected places. Both kinds of self-talk—the silent and the vocal (有声的)—seem to bring a range of benefits to our thinking.

3 . Industrial agriculture is often held up as the solution to feeding the world’s growing population. But small farms of about 25 acres or less produce over 70 percent of the world’s food. To raise awareness of the contribution of these farmers, a global photo exhibition, We Feed the World, is to open on October 12 in London.

“Industrial agriculture, which mainly focuses on a few types of crops, is not the only answer,” says art director Francesca Price. “We want these images to empower people to support their local food system.”

By growing traditional and non-commercial varieties, small farms support biodiversity and increase food security. With only 12 plants and five animal species making up 75 percent of what the world eats, food systems will be easily hurt by natural disasters and disease outbreaks. However, traditional farming communities are working to preserve their ancient seed diversity.

Keeping variety alive is very important in the face of climate change. In the future, researchers might need to get particular genes from—one variety to help another to adapt to warmer, stormier, or drier weather, or to save a prized variety from disease.

Contrary to the false impression held by the public, small farms that practise traditional agriculture can be highly productive. Studies show that the output of crops rises when there’s a wider diversity of crops being grown on a farm, and money is saved since the need for harmful fertilizer(化肥)and other chemicals is reduced.

“The photographs of family farmers may tell just a few local stories, but the message is universal,” says photographer Cheryl Newman. “I hope that the images will leave viewers thinking deeply about where their food comes from and the impact it has on the world around us.”