Adolf Tobeña



monograph · The Skeptical Razor


Exigent Doubt

Adolf Tobeña


Skeptics are always in the minority. Usually they appear puzzled and even shocked at the unalterable preeminence of credulity. They distill a gesture of weary frustration at the perseverance of those beguiled by the unending preaching of charming spells and unfounded hopes. Although the seduction and towing capacity of many doctrines, theories or prescriptions may crack noisily, new versions or slight alterations in the old ones renew the script and the devotional gathering. And often, with an overwhelming success. It happens in all fields: religions, political ideologies, philosophical theories or models of social reform or hygienic intervention adopt new clothes and promote processions eager to dispense with any contrast with precise and objective measures. With solid and replicable data.

It is like this, and will remain so. There is little to do except to keep active vectors for systematic and demanding doubt, in all situations and circumstances, despite their low advocacy. The recurring and excessive credulity propensity has its roots in properties of the neural networks. It rests on preferential attributes used by the brain to try to understand the physical and social environment. The brain produces, moment to moment, versions or representations of the world that should have consistency, continuity and a degree of predictability. Generally, they carry them and that reduces uncertainty and gives sufficient security to circulate with some profit in life. But there are surprises, incongruities and paradoxes. They appear within mental versions of the physical world and much more often yet, in versions of social environment. For two main reasons: because the degree of overlap between those world versions, between different brains, is far from consistent and social competition involves deception, distortion and deliberate manipulation. All of which multiplies the uncertainty. And therein lies the crux of the matter: we must generate, unavoidably, a margin of predictability and certainty in multiple and randomly distorted environments. Complex neural systems have mounted severe filters to detect inconsistencies and deceptions, but often they are not enough. Facilitating credulity automatisms helps also to mitigate the problem.

Because there are other drawbacks that do not depend on the reliability and filtering of external inputs. Let’s see one. Every night, in dreams, the brain ignites spontaneous versions of the world that do not conform to those properties of consistency, continuity and some predictability. Things happen in dreams that transgress all kinds of restrictions and natural limits: from interactions with nonexistent beings or with deceased characters from ancient times, to impossible time travel or physical transmutations totally unfeasible. But the brain makes these contents plausible and gives them credibility as they occur. Upon awakening they must be discarded, of course, if they’re still lurking in our minds, to try to regain consistency and plausibility in everyday interactions. To do this, to suppress the emergence of that bizarre imagery a neuro-cognitive attribute that experimental psychologists call “inhibitory control” is needed. Simple: devices to discard chaotic, absurd and implausible ideation, although it may seem that some flashes or ingredients perceived there carry signs or illuminating connections to discern deep mysteries. There is there, of course, an imperishable mine to the merchants of credulity. If everyone routinely makes legends with perfect normality, the field is prepared for those who can fabricate and sell them with the best persuasive arts.

Believers, that is, the majority of people, have an inhibitory control not completely efficient upon distorted, ambiguous or inconsistent mental elaborations, being those their own or from others. Skeptics have much stricter inhibitory controls. In children and the elderly there is less inhibitory control, hence those are the life periods with greater propensity for credulity. The region of the brain that deals with ways to implement the task of discarding or suppression of spontaneous “esoteric” or “magical” ideation are the lowest, anterior and lateral prefrontal cortex areas, in the left hemisphere. Just in front of the territories responsible for building the intricate articulatory sequence of verbal and gestual languages, with its efficient syntactic organization. People who scores high on credulity about the paranormal phenomena and the spiritual and transcendent features of human experiences, show a lower operation in those territories dedicated to “inhibitory control” of the bizarre or incongruous ideation (1). And often they also perceive and report many more signs, signals or connections loaded with special meaning to different varieties of visual input noise (2,3,4).

That is just one of the neural systems that have to handle or mitigate credulity. There are others which help shape a very important and distinctive feature of human temperament that had received little research attention until recently (5,6). Genuine skeptics, those who show a propensity to spontaneous and demanding empirical pragmatism are a minority, but they are indispensable to ensure and consolidate advances in solid knowledge. Hence, despite fatigue and frustration they have no choice but to persevere in the effort of demanding doubt. That should also apply to false skeptics: those activists of “anti-magic” or “anti-esoteric” beliefs but able to maintain partisan allegiances elsewhere.


1. Lindeman M, Svedholm AM, Riekki T, Raij TT and Hari R (2013) Is it just a brick wall or a sign from the universe? An fMRI study of supernatural believers and skeptics, SCAN, 8, 943-949.

2. Riekki T, Lindeman M and Raij TT (2014) Supernatural believers attribute more intentions to random movement than skeptics: an fMRI study, Social Neuroscience, 9, 4, 400-411.

3. Partos TR, CropperSJ and Rawlings D (2016) You don’t see what I see: individual differences in the perception of meaning from visual stimuli, PLOsOne, DOI:10.1371/journal.pone.0150615.

4. Krummenacher P, Mohr Ch, Haker H and Brugger P (2009) Dopamine, paranormal belief and the detection of meaningful stimuli, Journal of Cognitive Neuroscience, 22, 8, 1670_1681

5. Lindeman M and Lipsanen J (2016) Diverse cognitive profiles of religious believers and nonbelievers, The International Journal of Psychology of Religion, DOI: 10.1080/10508619.2015.1091695.

6. Tobeña A (2014) Devotos y descreídos: biología de la religiosidad, Valencia: PUV.


adolf tobeñaAdolf Tobeña

Catedrático de Psicología Médica y Psiquiatría.

Universidad Autónoma de Barcelona (España)



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