The latest bias to worry about: recency bias

For all the talk about how political and media bias distort people's perceptions of current events, another kind of bias may have an even greater impact: recency bias. Put simply, recency bias is the practice of giving disproportionate weight to the events of the recent past when formulating expectations and plans.

For instance, starting in 2008 the U.S. Federal Reserve increased the money supply sharply, and the rate of price inflation did not rise correspondingly. One result of this recent episode of expansionary monetary policy is that America became less vigilant about inflation — and it is now living with the consequences.

Another example: For decades, antisemitism seemed to be declining in American life. Many people assumed that this trend would continue. Yet violent attacks on synagogues and rabbis, one measure of anti-Semitic sentiment, have lately been on the rise.

If you were surprised by that development, you might have been a captive of your own recency bias: Antisemitism, including in its most violent forms, has been a longstanding feature of Western history, and it would be a mistake to assume it will go away. Of course it would be doubling down on recency bias to now assume that the rise in antisemitic attacks is going to continue.

The view that America was unprepared for a pandemic is another example of recency bias. The AIDS epidemic, which has killed possibly 35 million people worldwide in the last four decades, should have instilled the need for better planning, but many Americans saw that disease as something unlikely to happen to them. Major generalized pandemics, meanwhile, were perceived as something of the distant past.

Yet the more accurate, longer-term reality is this: Pandemics have recurred, albeit with varying lags, throughout human history.

I fear we are committing a form of recency bias by not focusing more on nuclear weapons and the policies surrounding nuclear proliferation and nuclear-weapons use. Atomic bombs have not been used against humans since 1945, and so for many people they are not a major concern, having been supplanted by fears of climate change. But a broader lesson of human history is that, if a weapon is available, sooner or later someone will use it.

Nonetheless, rooting out recency bias is difficult. Memory tends to deteriorate, and most people talk about current events far more than they talk about the broader span of history. There is a lot of debate about Brexit in British pubs, but not so much discussion of the Seven Years' War of the mid-18th century.

There are historical periods where recency bias makes sense. During Barack Obama's presidency, for example, you might have expected annual conflicts about health care policy between Democrats and Tea-Party Republicans. And you would have been right, as the parameters just didn't change that much. Of course, this success for recency bias is … recent, and thus to many people recency bias seems accurate. Much of American history since World War II has been a story of relative continuity, which makes recency bias all the more appealing.

In the last five years the U.S. seems to have had more inflection points — but even these have been rooted in the more distant past. Donald Trump's administration seemed highly unusual compared to Obama's or George W. Bush's. At the same time, it featured many elements from 19th-century American politics, such as extreme mudslinging, populism, a highly partisan press and a general lack of dignity.

Of course it is itself a kind of recency bias to note that many recent errors are the result of recency bias. As we get used to the world being weirder than expected, recency bias might mean overpredicting rather than underpredicting radical change.

In the meantime, history is rhyming, if not quite repeating itself. And understanding current events requires more than just a constant clicking of the refresh button on Twitter.