<blockquote>Proctor found that ignorance spreads when firstly, many people do not understand a concept or fact and secondly, when special interest groups – like a commercial firm or a political group – then work hard to create confusion about an issue.</blockquote>
via <a href="http://www.bbc.com/future/story/20160105-the-man-who-studies-the-spread-of-ignorance">BBC - Future - The man who studies the spread of ignorance</a>.