Meaning matching is the process of recognizing elements (referents) in the message and accessing our memory to find the meanings we have memorized for those elements. This is a relatively automatic task. It may require a good deal of effort to learn to recognize symbols in media messages and to memorize their standard meanings, but once learned this process becomes routine. To illustrate, think back to when you first learned to read. You had to learn how to recognize words printed on a page. Then you had to memorize the meaning of each word. The first time you saw the sentence "Dick threw the ball to Jane," it required a good deal of work to divide the sentence into words, to recall the meaning of each word, and to put it all together. With practice, you were able to perform this process more quickly and more easily. Learning to read in elementary school is essentially the process of being able to recognize a longer list of referents and to memorize their denoted meanings.

The idea of the machinelike brain has inspired and guided neuroscience since it was first proposed in the seventeenth century, replacing more mystical notions about the soul and the body. Scientists, impressed by the discoveries of Galileo, who showed that the planets could be understood as inanimate bodies moved by mechanical forces, came to believe that all nature functioned as a large cosmic clock, subject to the laws of physics. And they began to explain individual living things, including our bodily organs, mechanistically, as though they too were machines. This idea that all nature was like a vast mechanism, and that our organs were machinelike, replaced the two-thousand-year-old Greek idea that viewed all nature as a vast living organism, and our bodily organs as anything but inanimate mechanisms. But the first great accomplishment of this new "mechanistic biology" was a brilliant and original achievement.

There is little doubt that climate change will make it harder to produce enough food for the world's growing population and will alter the seasonal timing, availability, and quality of water resources. To avoid extending agriculture into already environmentally threatened areas, the current rate of agricultural productivity growth will have to be doubled, according to the World Bank, while minimizing the associated environmental damage. In the extreme event of a 5°C warming, agricultural productivity would be likely to decline throughout the world, particularly in the tropics, even with changes in farming practices. This could mean that more than 3 million additional people could die from malnutrition each year. Even the more likely 2°C warming would produce new weather patterns challenging conventional agricultural practices, and between 100 million and 400 million more people could be at risk of hunger.

Guilt must be distinguished from shame. The difference lies in how widely the bad feeling is generalized. Guilt focuses narrowly on the action, whereas shame spreads to the whole person. Guilt says, "I did a bad thing." Shame says, "I am a bad person." Research based on that distinction has repeatedly shown that shame is usually destructive, whereas guilt is usually constructive. This may be worth keeping in mind when you deal with your assistants and workers, or your children, or your students (or even your romantic partners). How do you criticize them when they do something wrong? Calling their attention to what they did wrong may seem necessary, but phrasing your criticism in terms of being a bad person (e.g., "you liar") is not nearly as constructive as allowing them to be a person who did a bad thing (e.g., "you shouldn't have lied").