One characteristic human foible is how easily we can falsely redefine what we experience. This flaw, called the Thomas Theorem, suggests, "If men define situations as real, they are real in their consequences."[2] Put another way, humans not only respond to the objective features of their situations but also to their own subjective interpretations of those situations, even when these beliefs are factually wrong. Other shortcomings include our willingness to believe information that is not true and a propensity to be as easily influenced by emotional appeals as reason, as demonstrated by the "North Dakota Crash" falsehood.[3] Machines can also be taught to exploit these flaws more effectively than humans: artificial intelligence algorithms can test what content works and what does not over and over again on millions of people at high speed, until their targets react as desired.[4]