Search Results for scepticism

The Biology of Scepticism (part 2)

Assuming that scepticism has biological roots, the next step consists on identifying the biological mechanisms that support the critical appraisal of the signals and their containing messages.

Evolutionary explanations make sense only in the light of genetics, which means, for a trait to be passed on to the next generation, it is a requirement that the code for that trait is passed on. But if there is a genetic code, what is it coding for?

In the light of our present knowledge in neurobiology, we know that the neural pathways and neurotransmitters that act in the brain are genetically determined, but during ontogeny and life development the inputs from the surrounding environment can also modulate the expression of these genes. Recent discussions in epigenetics question if these acquired traits can be passed on to the next generation. This would require that changes that occur in the brain of an individual could somehow be inserted in the gamete DNA as new information. At present it is difficult to see how somatic changes due to mental learning processes  during a life time could inserted and passed on through the genes of gametes. But it is reasonable to assume that there may be genes whose expression depends on the environmental stimuli.

For scepticism to be a genetically transmitted trait, it must rely on the morphology of brain areas, neuronal pathways or in the expression of neurotransmitters and the respective enzymatic and membrane protein machinery of the neurons and supporting brain cells.

How do we know which neurons makes us question the reliability of information? Does the brain have some sort of cognitive module that evaluates plausibility and information reliability?

Before delving in the neurobiology mechanisms that support scepticism, we must first delve into the psychological pathways involved in cognition and communication and to do so we need to go back to simpler examples as models to understand how the signals is deciphered and evaluated. How do animals “know” what information to ignore and what to take in?

Let us start with a simple model.

An individual exposed to the world is constantly sampling information which is stored in the memory.

As the memory becomes overloaded, the storage of information relies mainly on identifying common features of all the information that reach the senses and categorizing it in classes which shares common features.

When new information is perceived, it is compared against the data-base of cognitive categories.

Once it is included in a category, a refinement process occurs to distinguish the particularities of each piece of information in relation to the common denominator of the category. This is just like the process used by taxonomists to identify species.

If new information arrives which is not consistent with the stored memory database of categories, then two things can happen. It can be rejected or a new category is formed to accommodate it. However a category is persistent is it contains many members. As the category gets filled up it is frequently assessed by the mind’s categorization processes. If the category contains few members, its use for comparison purposes decreases and the neural pathways that refer to that category get weakened. In opposition the cognitive pathways which lead to categories that are frequently used as comparison standards get reinforced. Any inconsistent information will then take longer to be categorised. If it fits one of these mental categories it may be readily accepted, if not, it may require a further comparison with other existing categories, some of which may be fairly used by the cognitive comparison system.This could be eventually modelled by computers. (more about this later)

The work of  Grèzes et al., 2004; Lissek et al., 2008 suggested that three brain regions are active when deceptive acts are correctly (rather than incorrectly) detected.

  • the orbitofrontal cortex (involved in understanding other people’s mental states),
  • the anterior cingulate cortex (associated with monitoring inconsistencies
  • the amygdala (associated with detecting threats;).

But the results of Grèzes study can be interpreted in many different ways, for example, the activation of these brain areas may relate more to the perception of fairness than deception.

As I suggested in my earlier posting ( The biology of scepticism) , detection of deception relies on the ability to detect inconsistencies and comparing what is known and stored in the memory against the content of the novel information. So I hypothesise that structures involved with memory and categorization of information are more likely to be involved in detection of false information than structures involved with language.

Evolutionary significance of honesty

Scepticism is no more than a fancy word for the evolutionary mechanism for detection of deception and it protects us against making our decision based on unreliable or dishonest information. Wrong decisions can be costly.

Research on deception has focused mainly on two approaches:

  1. Detection of false propositions
  2. False belief task which is a prototypical task used in ToM which requires the subject to predict where a character will look for an object that has been displaced by another character unbeknownst to the first character.

Studies adopting the first approach where the  subject is required to detect explicit lies fall short of supporting this notion; 54% accuracy provides little protection from manipulation by deceivers, especially given that this above-chance accuracy is driven by the accurate detection of truths (mean accuracy = 61%), not lies (mean accuracy = 47%; Bond & DePaulo, 2006).

This result may be due to the fact that detection of deception is an ancient evolutionary mechanism, which has evolved well before language. Detection of deception may rely more on Theory of Mind and the evolution of intentionality than on language.

( to be continued)


Cited papers

Bond, C. F., & DePaulo, B. M. (2006)- Accuracy of deception judgements. Personality and Social Psychology Review, 10, 214–234.

Grèzes, J., Frith, C., & Passingham, R. E. (2004)- Brain mechanisms for inferring deceit in the actions of others. The Journal of Neuroscience, 24, 5500–5505.

Lissek, S., et al.(2008)-Cooperation anddeception recruit different subsets of the theory-of-mind network. PLoS ONE, 3(4), Article e2023. Retrieved from

The Biology of Scepticism

Humans and animals could not survive without beliefs. Beliefs are pieces of information that we assume to be true and as such they regulate our decision making in every social and ecological context. In humans and other animals, beliefs are created by the continuous sampling of the environment through our perception and as our experience of an event increases with frequency, the belief of its future occurrence becomes crystalized. But in humans, there are other sources of beliefs which seat on the transmission of ideas through communication. Such transmission is affected by external and internal factors. The external factors are cultural and based on meme repetition, ritualization and social position in the group. The internal factors are inherent to the individual and its psychology as its degree of credulity and acceptance of authority, its willingness to conform to the group dynamics and the meaning that each one of these memes has to the individual.

The strength to which each one of these memes is adopted and protected depends also on the qualities of the meme itself.  I have identified 6 factors that contribute to the stickiness of a meme:

  1. Emotional

Does the meme trigger strong emotional reactions?

Does it trigger positive emotions such as reward or pleasure, or negative emotions such as punishment, fear, guilt?

Is it memorable?  Is it salient?

That’s it value oneself as an individual?

Does it reduce anxiety due to unpredictability?

  1. Intuitive

An intuitive is one which agrees with our intuitions. For example does it agree with folk physics, biology, and psychology?

Does it agree with our cultural imprinting during a sensitive developmental phase?

  1. Causal

The meme explains the causes of events.

  1. Predictability

Does the meme offer some level of predictability to the random events of nature and social interactions, does reducing individual anxiety and stress levels?

  1. Reliability

Is the meme consistent in its narrative? Does it make sense in answering the main questions of life?

  1. Functionality

Does the meme offer pragmatic solutions to the questions of life?

 This list was created in function of the main questions that affect us all at different stages of our psychological development. Such questions can be divided into two categories: questions of empirical nature and existential questions.

Questions of empirical nature as things like; What or who causes the phenomenon?  How does it work? How often does it happen? What is it for? And they beg for answers that refer to causation and agency, mechanisms, patterns and utility.

Some of these questions are believed to occur in the minds of other animals, Not in the shape of verbal sentences but more in practical terms such as when a Capuchin monkey assesses the suitability of a stone to break a nut, or a New Caledonian Crow observes and learns the technique of using sticks to fish for grubs in decaying trees.

Animals have also some sort of pattern detection which allows them a certain level of predictability tweaking their behaviours in accordance with expected changes.

So it is reasonable to assume that some of these empirical questions may have roots in some evolutionary antecedents.

Existentialist questions, however, are more abstract and they focus on the issue of meaning, purpose and life as a finite entity. Questions about immortality and purpose are related to the philosophical approaches to telos.


















(Click on images to see them enlarged)



Beliefs that satisfy many of these conditions and answer these questions are likely to be persistent in the mind for they serve a purpose. Questioning such beliefs requires a considerable amount of scepticism, which does not come naturally in human minds. Or does it?

The history of philosophy has shown us that scepticism has been around for many centuries and therefore it is not a function of cultural evolution. In fact if belief may bring some evolutionary advantages in reducing stress, scepticism may also contribute to a balanced evaluation of information and a proper screening of the reliability of the information.

The assessment of signals is a behavioural characteristic present in many species. It is important that animals can detect dishonest signals. Those better at their detection and more likely to survive. Thus scepticism can also be seen as a natural mechanism biologically grounded to detect dishonest or misleading information. Both systems belief vs scepticism compete for place in the individual mind and natural selection might have selected one in detriment of the other in different situations. There are situations where belief conformity is advantageous for a social group, but scepticism may also prevent the group from setting themselves into danger.

A good leader would be one who can balance both traits and use them in the right situations.  This begs the question; is the tendency for belief and scepticism a biological tendency, rather than a cultural trait? Culture may emphasise this tendency which is expressed only in the presence of the right triggers.

Assessing individual differences in levels of scepticism versus credulity  is important for our modern society as it allows us to detect who is more susceptible to cheating . In practice the propagation of internet phishing schemes rely very much on the propensity of some people to be uncritical.

To investigate this question, it is necessary to see if there is psychological individual variation in the levels of credulity.

If that is true, the next step is to investigate if this variation is due to cultural or biological mechanisms?

Why would some individuals born and raised in the same cultural setting and studying the same University Course vary in their level of acceptance of memes and levels of critical reasoning?



The rejection of mainstream, widely accepted beliefs is usually perceived as scepticism, but we need to be clear about the meaning of this word for scepticism is used in different situations in loose ways. Usually it is perceived as an attitude of doubt in relation to the truth of received information.

If I receive an email from Nigeria telling me that the widow of the deceased president of a large company wants to share her inheritance with me because we share the same surname, I have good reasons to be sceptical. I’ll ask first where did they get my email? How do they know her connections to my family, and so on?  My scepticism prompts me to ignore that email and protect myself from some internet scam. However many people are susceptible to such scams. It is yet more difficult to assess the truth of the information when these tricks become even more complex and sound plausible. In such situations scepticism as a gut feeling is not enough. To protect myself I need to be able to ask questions which will enable me to assess the veracity of such information. Such questions depend not only on my tendency to be careful about received information, but also on some sort of mental training in assessing the reliability of information. Such training can be achieved through education and the practice of critical skills which helps us to analyse our own bias.

There are variations in the natural tendency to assess the reliability of information. Some humans may be more prone to readily accept it without scrutiny, whether others may be more careful in relation to embracing such information. This variation in human individuals begs the question; is it due to cultural or biological influences?

To answer this question, one needs to search for signs of scepticism in species other than humans, and understand which neurobiological mechanisms are involved in the tendency to question information. The biological explanation of scepticism requires an ultimate and a proximate explanation, based respectively in the evolutionary advantage of carefully evaluating information and which brain mechanisms are involved in such questioning which could be susceptible to variation and eventually genetically determined.

Scepticism and belief are two sides of the same coin. Whereas in humans, belief consists in accepting a piece of information as being true, scepticism questions that truth, which brings us to the need to understand the concept of truth and its importance in survival.


In philosophy, scepticism is a position which questions theories that discuss truth, knowledge and belief. These three concepts are closely related, in philosophy to have knowledge means that we have reasons to believe that the information that we uphold is true and the process to assess truth is through the acquisition of evidence.

Whenever a person holds a belief, that person assumes it is true, even if it is not in real life. If I believe in fairies, I hold it as being true. But is that knowledge? Not until I gather enough evidence for the existence of fairies.

The branch of philosophy concerned with theories of knowledge is called epistemology and it defines knowledge as justified belief. This requires the clarification of the concept “justification”.

The philosophical approach to scepticism is not relevant to the evolutionary discussion, but the history of philosophical scepticism offers an overview of how ancient is this attitude in the evolution of the human mind. The most ancient written records provide us with examples of sceptical questioning of the beliefs held at the time.

Before scepticism became a complex issue of epistemology, it originated as a questioning of authority which rested on unsupported assumptions. Seen this way, it is reasonable to assume that scepticism may have its roots well beyond the invention of writing. It might have been upheld by individuals inside a group which questioned the authority of tribal chiefdoms. Some individuals might have refused to abide by rules created by the caprices of tribal leaders. They would question such orders, costumes or taboos and require justifications for why should they follow it. This attitude might have been in the origin of abstract thought and complex metaphors.

A primitive sceptical dialogue would have been similar to this:

“You must do this because the chief says so”;

“And why should I believe the chief? On which authority is he requiring of me to do so?”

“ Because the chief is the voice of the spirits of the elders”

“ And how can he prove that it is true and he is not  lying to me just to make me offer my life for his own interests?”

The non-conformism shown by sceptical could simply be removed from the group through extermination or ostracizing, but the questioning would certainly be embraced by others who might have felt that unfairness was imposed upon them and thus the need to create justifications for the power of the chief becomes necessary. Oral justification might yet been more necessary when a critical mass of sceptics begins to rise among the group members. Then simply exterminating them would lead to a loss in valid members of the tribe, necessary to its defence against competing or threatening out-groups.

Philosophical scepticism entered the western culture through Pyrrhonism, a  school of philosophy with its roots in Classical Greece ( c. 360-275 BC), but scepticism had been expressed much earlier  well before the Greeks in Indian philosophy through the Carvaka materialists ( 6 century BC) who denied the concept of karma and rebirth. The Carvaka School is a current of Hinduism that rejects the supernatural through an emphasis on materialism and philosophical scepticism an d holding empiricism and perception as a necessary condition for the acquisition of knowledge.

So scepticism is not a new concept and developed during the Enlightenment, although it was during this period that Pyrrhonic scepticism was rediscovered and promoted.

A certain level of scepticism is thus necessary to the evaluation of the reliability of messages that may threaten the very existence of an individual. Under this approach, scepticism can then be treated as a mechanism to assess the reliability of information crucial for survival. The concept “information reliability” is the ecological equivalent of the philosophical concept of truth.

It is important not to confuse philosophical scepticism with irrational scepticism, which simply consists of doubting everything that is ascertained. This type of scepticism is exemplified in the rejection of evolution theory by creationists, or global warming by climate change sceptics, or the rejection of membership of the European Union by the so called Eurosceptics.

Note that in such circumstances, the word scepticism does not refer to the pursuing of knowledge through evidence, but rather a stubborn attitude to contradict mainstream beliefs.



There is a body of studies showing that cheating occurs in nature in many animal species, but it is important to distinguish between evolutionary cheating and intentional cheating.

The first refers to signalling systems which have evolved to mislead possible predators or competitors. The second refers to the presence of intentionality which requires a certain level of consciousness. For example, mimicry in nature is a form of cheating leading predators to confuse palatable prey with poisonous prey, but in this example when a scarlet king snake  mimics the poisonous coral snake, the mechanisms is not intentional. Scarlet king snakes became similar to coral snakes simply due to the processes of natural selection. However there are instance in animal behaviour which lead us to assume that there is certain level of intentional signalling. Some birds may simulate behaviours which lead a predator to assume the bird is injured, just to distract the predator from the position of the nest. It is not clear if this behaviour is intentional or just an automatic behavioural response that was positively selected through evolution as it brought some advantage to the survival of the offspring. However, even though the behaviour is fixed or instinctive, the decision to when to express it may bare some level of intentionality.  There are examples from studies of primate behaviour that some dishonest signals are indeed intentional. When dishonest signals are so widespread in nature, a mechanism of detection might have co-evolved with the signal. Cheating and detection can then be seen as a type of evolutionary arms race.

The mechanisms of cheating detection depend on which cues are used by each species as means of communication.  If communication is essentially based on sound, the receiver needs to develop mechanisms that detect faked signals in the sound waves. If communication is mainly visual, then the receiver of the message needs to detect small variations in the received images to detect what to trust. In humans and other primates were communication owns much to facial expressions, detection of lying is often based on subconscious perception of facial cues. This is why some people can say that they have a “feeling” that someone is lying, but they can’t really explain how they know it. Just as with pheromone detection, the perception of these visual cues does not necessarily reach our consciousness. Some people may be more accurate in this detection than others, but this is a system which has evolved by natural selection without interference of intentionality.

This natural tendency to detect cheats may be closely related to a propensity to the exercise of scepticism. My theory is that this propensity is an evolutionary by product built on the same neuronal pathways which enable detection of cheating.  The difference is that scepticism builds on the rise of consciousness and a tool that finds expression in the frontal cortex.

Note that the propensity for a particular trait does not mean that such trait is necessarily expressed. A propensity simply indicates that given the right environmental or social trigger the trait could be expressed, but if the trigger is never present it may never surface. For example some dogs may have a propensity to be more aggressive than others, but if they exist in environments that never require the expression of aggression, that trait may not be expressed. A propensity for a trait means that the trait is only expressed out of necessity.


(To be continued)

Clarifying SASHAR

Secularism, Atheism, Scepticism, Humanism, Agnosticism, Rationalism

SASHAR is a made-up word for the six concepts expressed above

When I started to get an interest on issues about religion, I noticed that different concepts were used as equivalent. For example in the atheist literature, it is common to find the SASHAR concepts as interchangeable or equivalent.But things are more complex that that. Here are some definitions that may help to understand the differences and similarities between these concepts:


It is common to hear people referring to secularists as an equivalent of atheism. This is wrong!
Secularism is the concept that government or other entities should exist separately from religion and/or religious beliefs. In one sense, secularism may assert the right to be free from religious rule and teachings, and the right to freedom from governmental imposition of religion upon the people within a state that is neutral on matters of belief. So the concept of a secular society involves the image of a religion free political and social system. Some ideas of modern secularism were developed by deists.

Deism holds that reason and observation of the natural world can determine that a supreme being created the universe but it does not intervene in human affairs nor suspends the natural laws of the universe. Deists typically reject supernatural events such as prophecy and miracles, tending to assert that God (or “The Supreme Architect”) has a plan for the universe that is not to be altered by intervention in the affairs of human life. Deists believe in the existence of God without any reliance on religious authority or holy book or the need for organized religion.

Secularism is not a modern phenomenon. Its intellectual roots are believed to go back to Greek and Roman philosophers such as Epicurus (341 – 270 BC) and Marcus Aurelius (121-180 AD). During the Dark Ages, secularism was embraced by some medieval Muslim thinkers. For example Averroes (1126-1198) a Muslim polymath born in Córdoba (Spain). He is also known as one of the founder of medical principles. But it is during the Enlightenment (18th century) that secularism becomes a widespread ideology promoting the separation of church and state. Many Christians support a secular state.
So to claim that you are a secularist because you are an atheist is a non sequitur, since many believers can also be secularists. However, if you are an atheist you are necessarily a secularist.


Scepticism refers to an attitude in relation to accepting information without subjecting it the scrutiny of reason, rejecting magical thinking, superstition and other irrational beliefs. Experience is often a poor guide to reality. Scepticism helps us to question our experience and to avoid being too readily led to believe what is not so.

There is indeed a philosophical school of thought known as Philosophical Scepticism. Sceptics critically examine the meaning systems of their times, and this examination often results in a position of ambiguity or doubt.

The earliest sceptics can be traced back to Pyrrho of Elis ( about 360 BC) a Greek philosopher who felt uneasy by the disputes between all philosophical schools of his day. According to a later account of his life, he became overwhelmed by his inability to determine rationally which school was correct. Zen Buddhism has also been described as a form of ancient eastern scepticism since it is not concerned with whether a thing exist or not.

Modern scepticism is associated with critical thinking and is one of the ground stones of the scientific method.

Some people, such as scientists for example, can reconcile their belief in a divinity or some sort of magical thinking about the power of crystals and the stars and some dose of scepticism about the events that punctuate their daily lives and the surrounding world. It is like if they compartmentalized their thought process. When they are in the lab they use the principles of scepticism and apply them with minutia to their scientific research, but once their hang their white coat behind the door and go home, leaving their scientific credentials together with heir scepticism in the drawer of their office desk.

Other people apply scepticism to all areas of their lives, making it difficult to accept the existence of entities with magical powers that could have an effect on their decisions and daily activities.

So, one could describe himself as being sceptical, but still accept the probability of the existence of some divinity. This brings us to the definition of agnosticism.


Agnostics are sceptical about the veracity of claims that ascertain the existence of any deity. In consequence, they are also doubtful about the truth of religious and metaphysical claims.
According to agnosticism it is impossible to make any sort of judgments about things that are unknown.

Agnosticism is much more than an attitude towards religion. The very word agnostic means without knowledge (a= without gnosis= knowledge). The word was coined by the English biologist Thomas Henry Huxley –also known as Darwin’s bulldog- in 1869. However the points of view sustained by agnosticism were promoted as early as the 500 years BC. Protagoras (490-420 BC) a pre-Socratic Greek philosopher is usually referred as one of the earliest known agonistics. “He is also believed to have created a major controversy during ancient times through his statement that “man is the measure of all things”. This idea was revolutionary for the time and contrasted with other philosophical doctrines that claimed the universe was based on something objective, outside the human influence” (see Wikipedia).
Agnosticism is the most rational standing when we cannot prove the existence or non-existence of things.
Logically it is impossible to prove a negative, therefore it does not make sense to see proof of the non-existence of something. However we can never be sure that this particular “something” does not exist. For example, until the discovery of New Zealand, Europeans believed that ALL swans were white. If someone suggested the existence of black swans, an agnostic response would sound like this: “ I cannot prove that black swans exist, but I cannot prove that they don’t exist either” . Then they found black swans in New Zealand!

Thus it mean that I could also believe in the existence of rainbow coloured swans? What would be the most reasonable answer?

Religious agnosticism applies the same line of reasoning to the existence (or non-existence) of a deity. Agnostics simply assume that it is impossible to know if God exists or not.

Some people would describe several categories and degrees of agnosticism which would ultimately lead to atheism.

Increasing levels of conviction about the non-existence of a deity.


The difference between agnosticism and atheism is that while the first claims that they do not know about the existence of a deity, the latter are sure that such a deity does not exist.
Nowadays atheism is often associated with the New Atheist movement (which I’ll discuss in detail in later blogs), but atheism is not a recent phenomenon. It was present in Classical Greece when the first philosophers attempted to explain the world in terms of the processes of nature instead of by mythological accounts. The 5th and 4th centuries BC were prolific in generating thinkers with atheistic views.

There are also a number of atheistic religions. They are considered atheistic because they have no God or deities. For example Paganism, Animism and Pantheism are atheistic religions in that sense that there is no personified Gods.
Some religions of the Far East focus on a contemplative life not revolving around the idea of gods. For example, Jainism, a religion believed to have raised about 3,000 BC does not have the concept of God. Other religions such as Buddhism, Taoism and certain sects of Hinduism also offer alternative life paths not cantered on the worshiping of a deity.


The term “humanism” can be confusing because it has expressed and different intellectual movements have been identified with it over time.
Humanism is philosophical school that focuses on human values and concerns focusing on moral virtues such as humanity.

The roots of modern humanism go as far back as to the 6th century BC expressed in an Indian school of thought known as the Carvaka system which was atheist in nature, It did not merely question whether there was a deity, it asserted that there was not!

In Ancient Greece, Protagoras was perhaps one of the philosophers closest associated with the ideals of humanism. During the Renascence and the Enlightenment humanism focused on reforming education promoting rationalism and emphasising scientific studies.
Humanists sought to create a citizenry (frequently including women) able to speak and write with eloquence and clarity and thus capable of engaging the civic life of their communities and persuading others to virtuous and prudent actions (see Wikipedia).
The term humanism can mean several things, but in the modern context of religious debate it is usually perceived as a secular ideology which advocates reason, ethics, and justice, whilst specifically rejecting supernatural and religious dogma as a basis of morality and decision-making. This type of humanism is known as Secular Humanism which congregates people that seek to explain the events of the world through a rational approach.

In recent years there has been a raise in humanist societies and action groups which attract secularists, atheists, agnostics and sceptics leading the lay man to assume that the modern humanistic movement is an umbrella for the expression of atheist ideals.

The International Humanist and Ethical Union (IHEU) is an organisation that represents humanist societies spread around the world. The member organisations must abide by the following statement:

Humanism is a democratic and ethical life stance, which affirms that human beings have the right and responsibility to give meaning and shape to their own lives. It stands for the building of a more humane society through an ethic based on human and other natural values in the spirit of reason and free inquiry through human capabilities. It is not theistic, and it does not accept supernatural views of reality.”


In its modern sense, rationalism is a view that appealing to reason as a source of knowledge or justification for all claims. According to rationalism, knowledge and truth are acquired through the deductive method. The reliance of this method varies which promotes different degrees of rationalism. For example some philosophers defended that morality was a pure rational exercise, while others accepted the role of emotions in determining what humans may find morally repugnant. So while moderate rationalism assumes that “reason has precedence over other ways of acquiring knowledge”, extreme rationalism claims that “reason is the only path to acquire knowledge”.