structural:expansion, information:filtering, information:highlighting
Popularity

Conspiracy beliefs are widespread around the world. In rural Africa, common targets of conspiracy theorizing include societal elites, enemy tribes, and the Western world, with conspirators often alleged to enact their plans via sorcery or witchcraft; one common belief identifies modern technology as itself being a form of sorcery, created with the goal of harming or controlling the people. In China, one widely published conspiracy theory claims that a number of events including the rise of Hitler, the 1997 Asian financial crisis, and climate change were planned by the Rothschild family, which may have led to effects on discussions about China's currency policy.

Conspiracy theories once limited to fringe audiences have become commonplace in mass media, contributing to conspiracism emerging as a cultural phenomenon in the United States of the late 20th and early 21st centuries. The general predisposition to believe conspiracy theories cuts across partisan and ideological lines. Conspiratorial thinking is correlated with antigovernmental orientations and a low sense of political efficacy, with conspiracy believers perceiving a governmental threat to individual rights and displaying a deep skepticism that who one votes for really matters.

Conspiracy theories are often commonly believed, some even being held by the majority of the population. A broad cross-section of Americans today gives credence to at least some conspiracy theories. For instance, a study conducted in 2016 found that 10% of Americans think the chemtrail conspiracy theory is "completely true" and 20–30% think it is "somewhat true". This puts "the equivalent of 120 million Americans in the 'chemtrails are real' camp". Belief in conspiracy theories has therefore become a topic of interest for sociologists, psychologists and experts in folklore.

Conspiracy theories are widely present on the Web in the form of blogs and YouTube videos, as well as on social media. Whether the Web has increased the prevalence of conspiracy theories or not is an open research question. The presence and representation of conspiracy theories in search engine results has been monitored and studied, showing significant variation across different topics, and a general absence of reputable, high-quality links in the results.

One conspiracy theory that propagated through former US President Barack Obama's time in office claimed that he was born in Kenya, instead of Hawaii where he was actually born. Former governor of Arkansas and political opponent of Obama Mike Huckabee made headlines in 2011 when he, among other members of Republican leadership, continued to question Obama's citizenship status.