For elephants, selective hunting converted a disadvantage into an asset and vice versa. Without human hunting, tusk bearing was an asset and tusklessness a disadvantage. Heavy ivory hunting reversed their roles. Cutting a tusk off a live, wild elephant is a task recommended only for the suicidal, so ivory hunters killed elephants to get at the tusks safely. Numbers of elephants dropped so low that, in the twentieth century, conservationists launched efforts to save the species through the creation of national parks and bans on hunting. But the interplay of poverty, weak law enforcement, and global demand fueled poaching in Africa, even in protected areas. Poachers wanted nothing from elephants except tusks. A once-rare genetic feature, tusklessness, grew far more common as poachers made its advantages outweigh its disadvantages. Tuskless elephants usually lived to reproduce; tusked elephants often did not.

Maps select and frame a particular piece of geography. More important, and more surprising, is this: every map frames a question, which then becomes the question. Every map then responds to its own question by selecting those data deemed relevant. No map shows everything; what is selected reveals the mapmaker's purpose. But maps do more than reflect intention. They also create a mindset. They lead us toward a particular view of reality. What maps show us — "the answer" they set forth to the question they frame — exerts a powerful influence on our perception, especially since maps still carry an aura of being reliable and bias-free. What we're saying is this: maps are verbs. They may seem to be tactile objects, documents we can handle or fold — nouns — but don't be fooled. In persuasively framing questions and selectively supplying answers, they act; they function as agents. This is "the power of maps."

One way people simplify their decisions and make them more manageable is to reduce the number of consequences they consider. They're especially likely to ignore consequences that are thought to affect only a few people. But consequences that affect only a few people can be serious. For example, a highly beneficial drug may have positive consequences for many and adverse consequences for only a few people. But what if those few people could die from side effects of the drug? Obviously, you wouldn't want to ignore such serious consequences no matter how few people are affected. In attempting to consciously deal with this situation, it helps to consult a broad range of people who have a stake in the decision you're making. Invite input from all interested parties, especially those who disagree with you and those with the most to lose. Ask them what consequences they're concerned about and why. Then, incorporate these consequences in your decision making.

In the early stages, cherries are too tart to eat, but as the cycle progresses, the sugar content of the fruit increases, making them more appealing to most palates. Professional cherry growers time their harvests so that the fruit appears in supermarkets near the peak of the ripening cycle. Invariably, however, cherries on trees growing in public parks are picked when they are barely sweet enough to be edible. Why don't people wait? Professional cherry growers plant their trees on private land, and trespassers who pick cherries from them are subject to legal sanctions. These growers have no incentive to harvest their fruit prematurely. But the incentives are different in public parks, where anyone is free to pick cherries. And although everyone would be better off if the fruit were allowed to ripen, anyone who waited that long would find no cherries to pick.

When reintroducing foods, try different preparation and cooking methods to make the food more appealing. Surrounding a rejected food with flavors the child normally likes, like cheese or bacon, can be especially effective. This was a favorite trick in my own household when I was growing up. "If I'd melted cheese on it, you guys would have eaten shoe leather," my dad told me when I asked him why he thought we always ate our vegetables. I've spoken to other parents who swear that garlic, salt, and pepper is a combination enticing enough to get their kids to eat almost everything. The important thing is to get children accustomed to eating a diverse assortment of fresh vegetables and fruits. As long as the garnishes are made from real ingredients, a few extra calories that help them enjoy the experience is perfectly fine.