President Barack Obama has been a busy man while in office: he concocted a fake birth certificate to hide his true identity as a foreigner, created “death panels” to determine who would live and who would die under his health care plan, conspired to destroy religious liberty by mandating contraceptives for religious institutions, blew up the Deepwater Horizon offshore drilling rig to garner support for his environmental agenda, masterminded Syrian gas attacks as a pretext to war, orchestrated the shooting of a tsa agent to strengthen that agency's powers, ordered the Sandy Hook school massacre to push through gun-control legislation, and built concentration camps in which to place Americans who resist.

Do people really believe such conspiracy theories? They do, and in disturbingly high numbers, according to recent empirical research collected by University of Miami political scientists Joseph E. Uscinski and Joseph M. Parent and presented in their 2014 book American Conspiracy Theories (Oxford University Press). About a third of Americans, for example, believe the “birther” conspiracy theory that Obama is a foreigner. About as many believe that 9/11 was an “inside job” by the Bush administration.

The idea that such beliefs are held only by a bunch of nerdy white guys living in their parents' basements is a myth. Surveys by Uscinski and Parent show that believers in conspiracies “cut across gender, age, race, income, political affiliation, educational level, and occupational status.” People on both the political left and right, for example, believe in conspiracies roughly equally, although each finds different cabals. Liberals are more likely to suspect that media sources and political parties are pawns of rich capitalists and corporations, whereas conservatives tend to believe that academics and liberal elites control these same institutions. GMO conspiracy theories are embraced primarily by those on the left (who accuse, for example, Monsanto of conspiring to destroy small farmers), whereas climate change conspiracy theories are endorsed primarily by those on the right (who inculpate, for example, academic climate scientists for manipulating data to destroy the American economy).

Group identity is also a factor. African-Americans are more likely to believe that the CIA planted crack cocaine in inner-city neighborhoods. White Americans are more likely to believe that the government is conspiring to tax the rich to support welfare queens and turn the country into a socialist utopia.

Encouragingly, Uscinski and Parent found that education makes a difference in reducing conspiratorial thinking: 42 percent of those without a high school diploma are high in conspiratorial predispositions, compared with 23 percent with postgraduate degrees. Even so, that means more than one in five Americans with postgraduate degrees show a high predisposition for conspiratorial belief. As an educator, I find this disturbing.

Other factors are at work in creating a conspiratorial mind. Uscinski and Parent note that in laboratory experiments “researchers have found that inducing anxiety or loss of control triggers respondents to see nonexistent patterns and evoke conspiratorial explanations” and that in the real world “there is evidence that disasters (e.g., earthquakes) and other high-stress situations (e.g., job uncertainty) prompt people to concoct, embrace, and repeat conspiracy theories.”

A conspiracy theory, Uscinski and Parent explain, is defined by four characteristics: “(1) a group (2) acting in secret (3) to alter institutions, usurp power, hide truth, or gain utility (4) at the expense of the common good.” A content analysis of more than 100,000 letters to the New York Times in 121 years turned up three pages' worth of such conspirators, from Adolf Hitler and the African National Congress to the World Health Organization and Zionist villagers, catalogued into eight types: Left, Right, Communist, Capitalist, Government, Media, Foreign and Other (Freemasons, the AMA and even scientists). The common theme throughout is power—who has it and who wants it—and so the authors conclude their inquiry with an observation translated by Parent from Niccolò Machiavelli's The Prince (a conspiracy manual of sorts), for “the strong desire to rule, and the weak desire not to be ruled.”

To those who so conspire, recall the motto of revolutionaries everywhere: sic semper tyrannis—thus always to tyrants.