Enough For Everyone, But We Can't See It

Just as dietary habits suited to the Stone Age are disastrous in a world of fast food, so may primitive zero-sum habits of mind be unsuited the everybody-wins nature of modern trade and immigration:

This is the world our minds evolved to understand. To this day, we often see the gain of some people and assume it has come at the expense of others. Economists have argued for more than two centuries that voluntary trade, whether domestic or international, is positive sum: it benefits both parties, or else the exchange wouldn't occur. Economists have also long argued that the economics of immigration -- immigrants coming here to exchange their labor for money that they then exchange for the products of other people's labor -- is positive sum. Yet our evolutionary intuition is that, because foreign workers gain from trade and immigrant workers gain from joining the U.S. economy, native-born workers must lose. This zero-sum thinking leads us to see trade and immigration as conflict ("trade wars," "immigrant invaders") when trade and immigration actually produce cooperation and mutual benefit, the exact opposite of conflict.

Confounding our judgements further are the habits of group identification that formed in a world of scarce resources and small, close-knit communities:

As primates, which are a very social order, our ancestors lived in relatively small groups in which everyone knew everyone else. Our minds are adapted to deal with populations of that size. Our ancestors made strong distinctions between members of the in-group and outsiders, and we still make such distinctions today -- social psychologists can create in-group and out-group feelings based on virtually any arbitrary difference between populations.

The in-group and out-group intuitions help fuel opposition to expanded trade and immigration. The public intuitively believes that the beneficiaries of such policies will be foreigners, and it is easy to arouse suspicion about those who are not part of our in-group. When coupled with zero-sum thinking, this is a powerful political tool. For instance, a domestic industry or collection of domestic workers, when having difficulty competing with foreign or immigrant competitors, can use innate dislike of outsiders when advocating for increased barriers.

Evolution, Immigration and Trade [Washington Post]