Extreme attitudes are easier to understand, communicate, memorise, and retrieve from memory and more likely to affect behaviour compared to non-extreme attitudes.31 Further, “[p]eople with extreme attitudes often view the topic as more important, are more committed to the issue, and are more resistant to change than people with less extreme attitudes”.32 Another relevant observation is that individuals on the extreme ends of the political spectrum (far left and far right) have greater proclivity to conspiracy theories.33
Conspiracist and extremist propaganda are often built on an underlying grand narrative of a polarised, binary, black-or-white, and good-or-evil world excised of middle ground or grey areas. The reality is not binary and does not fit into neat categories; neither do scientific and other evidence-based enquiries that take pride in the virtue of approximation to reality if not correspondence to it. This commitment to evidence and facts in scientific and historical enquiries translates into a communication hazard in that it systematically precludes sharply defined, plain, binary statements.34
To shed light on how this cognitive mechanism affects narratives of conspiracy theory, consider the example of corruption in the pharmaceutical industry. Cases involving corruption, ghost-writing clinical trial articles, bribing medical practitioners, government officials, and other decision-makers, influencing politicians through the funding of their election campaigns, and influencing scientific research through funding are abundant in the pharmaceutical industry all over the world. Indeed, this corruption may have contributed to the deaths of thousands and to serious monetary loss and health burdens on millions of people.35 Evidence-based approaches to explain this issue will distinguish between different contexts where these happen. Different countries have different laws and regulatory contexts that govern the industry and regulate its relationship with other medical institutions. These differences in regulatory environments may render one country more prone to corruption than another. Moreover, such an explanation shall distinguish between different practices that lead to corruption: practices involving corruption in research funding may have different explanations and solutions from those involving funding of political campaigns. Evidence-based enquiry does not provide an extreme, yes-or-no, good-or-evil, conceptually neat and tidy answer to this phenomenon. The narrative of conspiracism, however, is constructed upon a good-or-evil binary worldview of a secret cabal of a few big, sinister players who control the whole industry, politicians, and public institutions and who hide effective medicines from the public and produce drugs that do more harm than good. Understanding, processing, and remembering a global Big Pharma conspiracy is more energy-efficient for the brain compared to a collection of diverse and complex explanations for each corruption case that sometimes contradict each other.36
To understand the role of cognitive extremity in narratives of violent extremism, I mention the example of a centuries-old conundrum of the Muslim underdevelopment (however it is understood). An evidence-based and methodologically sound explanation would consider a plethora of factors. For beginners, such an explanation will place into doubt the validity of the question itself since the question presupposes the existence of a homogeneous conceptual category of ‘Muslims’ that share major ideological beliefs, psychological traits, cultural characteristics, and historical journeys. An evidence-based inquiry will necessarily dismantle this overarching category of ‘Muslim’ and analyse underdevelopment according to more concrete factors. It may conclude that what contributes to poverty in a Somali village near its border with Kenya might be entirely different from the reason behind poverty in outskirts of Dhaka, Bangladesh. Similarly, a critical ethnographic study might suggest that an Indian Muslim and her Hindu neighbour have more in common in terms of their religious beliefs and practices and cultural traits than an Indian Muslim and a Turkish Muslim. These kinds of evidence-based analyses would result in numerous, fragmented, nuanced, detailed, and sometimes contradictory explanations. An alternative approach is provided by extremists: that the current “Muslim” plight is a result of the “infidel invaders” against the “Muslim ummah”.37 This master narrative is built upon and squarely fits within an age-old conceptual schema that divides the world into the binary of God-or-Satan, good-or-evil, believer-or-non-believer, and a perennial and eternal battle between Islam and Kufr that existed from time immemorial up to Muhammad’s battles with Jewish and Christian kafirs, to the Crusades, European colonisation, and, more recently, the US invasion of Afghanistan and Iraq. Islamists’ answer is extreme, strong, clear-cut, and in tune with historical myths, prototypes, and metaphors. Research indicates that graduates of engineering who have more propensity and exposure to neat, definitive, and perfect models are overrepresented among members of both violent Islamist extremists and right-wing extremists. Not unexpectedly, graduates of social sciences and humanities are almost absent in both groups. This predilection to radicalisation is often associated with this clear-cut, binary, simple view of the world and project-oriented mentality toward social change so endemic to engineering as opposed to social sciences.38
 Howard Lavine, Eugene Borgida, and John L. Sullivan, “On the relationship between attitude involvement and attitude accessibility: Toward a cognitive‐motivational model of political information processing”, Political Psychology 21.1 (2000): 81–106.
 Lyn M. Van Swol et al., “The language of extremity: The language of extreme members and how the presence of extremity affects group discussion”, Journal of Language and Social Psychology 35.6 (2016): 603–627.
 Jan-Willem Van Prooijen, André P.M. Krouwel, and Thomas V. Pollet, “Political extremism predicts belief in conspiracy theories”, Social Psychological and Personality Science 6.5 (2015): 570–578. On the impacts of education on attitude extremity see Michael D. Makowsky and Stephen C. Miller, “Education, intelligence, and attitude extremity”, Public Opinion Quarterly 78.4 (2014): 832–858.
 Social psychological research indicates that cultures vary on the degree to which they interpret the world binarily. Numerous experiments have indicated a higher proclivity of people in Western societies to think in binary terms compared to people in Eastern countries. See Richard E. Nisbett et al., “Culture and systems of thought: Holistic versus analytic cognition”, Psychological Review 108.2 (2001): 291–310; Richard Nisbett, The Geography of Thought: How Asians and Westerners Think Differently… and Why (Simon and Schuster, 2004).
 Sergio Sismondo, “Epistemic corruption, the pharmaceutical industry, and the body of medical science”, Frontiers in Research Metrics and Analytics 6 (2021): 2.
 Robert Blaskiewicz, “The Big Pharma conspiracy theory”, Medical Writing 22.4 (2013): 259–261. Indeed, the evidence-based approach confirms the existence of corruption in the industry but avoids inferring a wholesale conclusion about a Big Pharma conspiracy. In other words, the evidence-based approach refrains from inferring from the existence of real conspiracies to conspiracy theories. Hence the need to distinguish between conspiracies that have proven to be true from conspiracy theories. The fact that there have been real conspiracies does not prove unfounded theories about conspiracies.
 Jeffry Halverson, Steven Corman, and H. Lloyd Goodall, Master Narratives of Islamist Extremism (Springer, 2011).
 See Gambetta and Hertog, Engineers of Jihad.