If Paul Revere were alive this week and employed on late night cable news, his midnight ride through the airwaves would no doubt have included the exclamation, “The tariffs are coming! The tariffs are coming!” And not just tariffs on aluminum and steel. Now we have news that the president plans to levy tariffs on at least $50 billion in Chinese imports.

In his New York Times bestseller "Conquer the Crash," Robert Prechter listed some events that typically occur during times of increasingly negative social mood. Here’s the one that pertains to the tariffs:

“Protectionism is correctly recognized among economists of all stripes as destructive, yet there is always a call for it when people’s mental state changes to a defensive psychology. … If one country does not adopt protectionism, its trading partners will. Either way, the inevitable dampening effect on trade is inescapable. You will be reading about protectionism in the newspapers.”

And reading about it we are. Prechter’s socionomic theory proposes that trade tensions reflect a shift in social mood from ebullience and expansion to fear and defensiveness. Our primary metric of social mood, national stock indexes, have trended net lower since late January in the U.S., indicating a turn in social mood toward the negative.

The Trump tariffs are presently unpopular among economists, the public, leading retailers, leaders of other countries and even members of the president’s party (although there is a smattering of support from the other side of the aisle). When mood becomes more negative, protectionism will find greater political traction.

For its part, mood in China has been trending toward the negative for more than a decade. Its Shanghai Composite stock index is down 45% from its 2007 all-time high. Nearer-term the index has fallen more than 35% from its lower high in 2015. Investor sentiment indicators also reflect a dismal mood in the country. At a speech in Davos last year, China’s President Xi Jinping said, “No one will emerge as the winner of a trade war.” Regardless of the veracity of that statement, mood is such in China that retaliatory actions are now on the table.

As my colleague Murray Gunn observed in a recent article, global trade has been deteriorating for more than a year, as reflected in a decline in the Morgan Stanley Global Trade Leading Indicator. The new tariffs and more belligerent attitudes toward global trade are symptoms of the defensive psychology behind that decline, not its cause.

Declining global trade prospects, falling stock prices and protectionism are but three manifestations of negative social mood. Others are more benign, such as trends toward a general preference for conservative clothing fashions, dull car colors, somber or angry music, more traditional baby names, antiheroes in fiction and film, and fewer conceptions, leading to fewer births. Yet others are more severe, such as the potential for greater conflict, economic slumps and contractions in employment.

Our institute’s recent books "Socionomic Causality in Politics" and "Socionomic Studies of Society & Culture" chronicle numerous other signs to look for in trends of positive or negative social mood. In each case, if you’re prepared for it, you can either join in the trend and thrive or get out of the way and remain safe from the charging herd.

Matt Lampert is the director of research at the Socionomics Institute, a think tank that uses data on social mood to understand and anticipate social trends. He’s a contributing author to Socionomic Causality in Politics, an Amazon #1 bestseller in behavioral psychology.Matt Lampert is the director of research at the Socionomics Institute, a think tank that uses data on social mood to understand and anticipate social trends. He is a contributing author to the recent books Socionomic Causality in Politics, an Amazon #1 bestseller in behavioral psychology, and The Socionomic Theory of Finance.