Why pausing intuitive thinking favours complex reasoning

One of the most recent and sig­nif­i­cant efforts to unrav­el the mys­ter­ies of how our psy­che works is the rapid progress made in the field of cog­ni­tive psy­chol­o­gy. These advances have rev­o­lu­tionised our under­stand­ing of the human mind, mark­ing a new era in the study of men­tal mech­a­nisms. One of the most notable con­tri­bu­tions comes from Daniel Kah­ne­man, co-founder of behav­iour­al eco­nom­ics and win­ner of the 2002 Nobel Prize in Eco­nom­ics. His major con­tri­bu­tion lies in the dis­tinc­tion he made between our dif­fer­ent men­tal states, a bold and now indis­pens­able hypoth­e­sis. He pro­posed that our men­tal states can oscil­late over time between two dia­met­ri­cal­ly opposed modes of think­ing: the first, called Sys­tem 1, is fast, intu­itive and auto­mat­ic, while the sec­ond, Sys­tem 2, is char­ac­terised by its slow­ness, in-depth analy­sis and thought­ful nature. 

To illus­trate these two men­tal sys­tems, let’s take a sim­ple exam­ple: when asked “What is 2 + 2?”, Sys­tem 1 pro­vides the answer using a men­tal rou­tine. But if we ask “What is 17 x 24?”, Sys­tem 2 is required to mobilise men­tal resources to break down the prob­lem into sim­pler com­po­nents. How­ev­er, the tran­si­tion from Sys­tem 1 to Sys­tem 2 is not auto­mat­ic: it requires the detec­tion of con­flict or poten­tial error, fol­lowed by a more or less pow­er­ful block­ing of intu­itive responses.

Cog­ni­tive psy­chol­o­gy high­lights a sub­tle tran­si­tion between the two major sys­tems of thought, a shift based on a fun­da­men­tal mech­a­nism, often at work in the shad­ows of our con­scious­ness, which we will call frontal inhi­bi­tion. As we will fur­ther explore, this direct ema­na­tion of pre­frontal cor­tex activ­i­ty plays a key role in sup­press­ing reflex­ive impuls­es and neu­tral­is­ing auto­mat­ic respons­es. It thus paves the way for the emer­gence of more thought­ful, delib­er­ate think­ing – the very think­ing we asso­ciate with reason.

To put it more sub­tly, intel­li­gence can­not be reduced to the brain’s abil­i­ty to analyse and process data ¹; it lies much deep­er, in the sub­tle alche­my through which the frontal lobes – and espe­cial­ly the pre­frontal cor­tex – exer­cise their role as guardians of dis­cern­ment, fil­ter­ing the influx of infor­ma­tion through the salu­tary prism of doubt. Far from being a sign of weak­ness, this doubt becomes the emblem of cog­ni­tive ele­gance: a serene vig­i­lance, an inti­mate resis­tance to the decep­tive seduc­tions of evi­dence and com­mon sense. To evoke frontal inhi­bi­tion is to name this deci­sive func­tion by which the mind sus­pends automa­tism, restrains the momen­tum of first impres­sions, and rejects hasty respons­es or inap­pro­pri­ate behav­iour when cir­cum­stances require it. In short, frontal inhi­bi­tion is, in the silence of men­tal func­tion­ing, the dis­creet focus of our lucidity.

Olivi­er Houdé’s research² has shed new light on the pro­gres­sive devel­op­ment of cog­ni­tive inhi­bi­tion in chil­dren, based in par­tic­u­lar on clas­sic tests designed to assess the con­cept of con­ser­va­tion – whether in terms of quan­ti­ty, length or weight. Take, for exam­ple, the weight con­ser­va­tion test, in which a child is pre­sent­ed with two iden­ti­cal balls of mod­el­ling clay. Then, in front of the child, one is flat­tened into a thin pan­cake while the oth­er retains its com­pact shape. When asked, “Do they still weigh the same?”, chil­dren who have not yet acquired the con­cept of con­ser­va­tion will often answer that the pan­cake weighs less, mis­led by the flat, thin appear­ance of the dough. Con­verse­ly, chil­dren who have devel­oped this abil­i­ty will under­stand that the mass remains unchanged, despite the change in shape. Build­ing on Jean Piaget’s work, Olivi­er Houdé shows how chil­dren grad­u­al­ly learn that appear­ances can some­times be deceiv­ing and that cer­tain fun­da­men­tal prop­er­ties remain sta­ble despite chang­ing forms. Implic­it­ly, this evo­lu­tion in think­ing over time pow­er­ful­ly illus­trates the essen­tial role of frontal inhibition—the abil­i­ty to sus­pend over­ly hasty intuition—which, in our world sat­u­rat­ed with images and quick judge­ments, proves to be one of the most reli­able defences against misinformation.

This evo­lu­tion in think­ing over time pow­er­ful­ly illus­trates the essen­tial role of frontal inhi­bi­tion which proves to be one of the most reli­able defences against misinformation.

As such, one of the major – if not the most press­ing – goals of edu­ca­tion should be to nur­ture, refine and ele­vate this unique­ly human fac­ul­ty of cog­ni­tive inhi­bi­tion: the silent pow­er to sus­pend our ini­tial impulse, to inter­rupt the imme­di­ate flow of auto­mat­ic respons­es and make way for delib­er­a­tion and self-con­trol. Long neglect­ed in favour of more spec­tac­u­lar skills, this inner dis­po­si­tion is nev­er­the­less the foun­da­tion of inner free­dom, which allows the mind to break free from the chains of impul­siv­i­ty. Recent advances in brain imag­ing have iden­ti­fied its loca­tion in the lim­i­nal area of the pre­frontal cor­tex – the part of the brain that devel­ops par­tic­u­lar­ly late, well after the mat­u­ra­tion of the more prim­i­tive struc­tures that orches­trate the rapid, intu­itive and emo­tion­al activ­i­ty of Sys­tem 1. While the brain as a whole devel­ops grad­u­al­ly dur­ing child­hood and ado­les­cence, the frontal lobes progress slow­ly, slow­ly shap­ing our abil­i­ty to delay action, weigh con­se­quences and con­trol our passions.

The more grad­ual devel­op­ment of the frontal lobe brain large­ly explains the behav­iour­al char­ac­ter­is­tics of ado­les­cence: impul­sive­ness, insta­bil­i­ty and aver­sion to delib­er­a­tion. Although the brain appears to have reached its archi­tec­tur­al form by the age of 18 to 21, the pre­frontal cor­tex con­tin­ues to refine its net­works for anoth­er ten years or so through the myeli­na­tion of nerve fibres, synap­tic prun­ing and the grad­ual den­si­fi­ca­tion of neur­al con­nec­tiv­i­ty. It is there­fore only around the age of 25, some­times 30, that the frontal lobes reach true matu­ri­ty, giv­ing the indi­vid­ual full capac­i­ty for reg­u­la­tion, fore­sight and moral clar­i­ty. It is at this moment, often dis­creet and unno­ticed, that human thought becomes tru­ly for­ward-look­ing, and that self-aware­ness, freed from the tur­moil of the imme­di­ate present, can aspire to the enlight­ened exer­cise of freedom.

This new knowl­edge sheds deci­sive light on the cen­tral role of this fac­ul­ty, not only when it comes to aca­d­e­m­ic suc­cess, but also in reg­u­lat­ing emo­tions and, more broad­ly, in ensur­ing a har­mo­nious social life. In the wake of Olivi­er Houdé’s work, we can there­fore argue for a gen­uine “pre­frontal cor­tex edu­ca­tion”: ear­ly train­ing, from the age of three or four, of this exec­u­tive func­tion, which is the cor­ner­stone of reflec­tive think­ing. For in a world sat­u­rat­ed with dig­i­tal stim­uli and press­ing automa­tisms, stim­u­lat­ing the devel­op­ment of cog­ni­tive inhi­bi­tion is no longer a sim­ple edu­ca­tion­al choice – it is an urgent neces­si­ty, the pre­req­ui­site for the enlight­ened exer­cise of free will.

In the con­text of philo­soph­i­cal scep­ti­cism, par­tic­u­lar­ly among ancient scep­tics such as Pyrrho and Sex­tus Empir­i­cus, men­tal inhi­bi­tion plays a cen­tral role in deci­sion-mak­ing, man­ag­ing our atten­tion span and con­trol­ling our auto­mat­ic respons­es. For these pio­neers of frontal lobe strength­en­ing, cog­ni­tive inhi­bi­tion allows for the vol­un­tary sus­pen­sion of judge­ment (epoché), caused by an inhi­bi­tion of men­tal assent in the face of uncer­tain propo­si­tions. In oth­er words, scep­tics choose not to decide between con­tra­dic­to­ry the­ses by men­tal­ly inhibit­ing their nat­ur­al incli­na­tion to believe or judge.

This inhi­bi­tion is active; it is not the result of an inabil­i­ty to judge, but rather a choice, a con­scious deci­sion not to do so. For this rea­son, it requires the involve­ment of the frontal lobes. By free­ing itself from dog­ma­tism and the dis­tur­bances caused by unfound­ed opin­ions, frontal inhi­bi­tion thus allows us to achieve atarax­ia (peace of mind result­ing from the absence of belief).

This phi­los­o­phy of qui­et doubt dif­fers from mod­ern scep­ti­cism (such as Mon­taigne³ or Descartes and his famous “method­i­cal doubt”), which doubts not in order to sus­pend judge­ment, but rather to access the truth. Con­verse­ly, Pyrrhon­ism doubts in order to free itself from the need for truth. Through this debate on the role of scep­ti­cism, two major func­tions of the frontal lobes emerge: on the one hand, the abil­i­ty to inhib­it the mind’s over­ly hasty flash­es of insight, and on the oth­er, the abil­i­ty to orches­trate our thoughts method­i­cal­ly in order to bring us as close as pos­si­ble to the truth. By com­par­ing Pyrrhon­ian scep­ti­cism with cer­tain mod­ern fig­ures, or even with relat­ed tra­di­tions such as empiri­cism, phe­nom­e­nol­o­gy, exis­ten­tial­ism and Bud­dhism⁴, a secret thread emerges, an under­ly­ing pat­tern that con­nects them all: the recog­ni­tion of uncer­tain­ty not as a weak­ness, but rather as a path to inner free­dom and access to serenity.

In short, frontal inhi­bi­tion is at the heart of exec­u­tive con­trol in human beings, nur­tur­ing essen­tial cog­ni­tive flex­i­bil­i­ty, sup­port­ing work­ing mem­o­ry and facil­i­tat­ing the thought­ful plan­ning of our actions. With­out this capac­i­ty for inhi­bi­tion, Sys­tem 2 would be con­tin­u­al­ly over­whelmed, short-cir­cuit­ed by the imme­di­ate and auto­mat­ic respons­es of Sys­tem 1. Thus, we can say that the exis­tence of frontal inhi­bi­tion con­fers at least three car­di­nal virtues, which are the true pil­lars of crit­i­cal thinking:

• Intel­lec­tu­al humil­i­ty: know­ing the lim­its of one’s knowl­edge – a form of dis­creet wis­dom that allows us to say, “I know what I know and what I don’t know.” 
• Restraint in judge­ment: the art of know­ing how to sus­pend con­clu­sions and not give in to the temp­ta­tion to jump to conclusions;
• Revi­sion of beliefs: the abil­i­ty to ques­tion, sus­pend or even read­just what we believe to be cer­tain­ties in the face of new information.

Ulti­mate­ly, frontal inhi­bi­tion is now emerg­ing as an essen­tial cog­ni­tive tool: it is both a weapon against judge­ment bias and a method of resist­ing the allure of illu­sion and false­hood, as well as an exis­ten­tial stance, at the cross­roads of phi­los­o­phy and spir­i­tu­al­i­ty, allow­ing us to move for­ward with­out being shack­led by dog­ma. It remains, as Pyrrho already sensed, a path to lucid­i­ty – and, some­times, to that inner peace that only the sus­pen­sion of judge­ment can bring.

Exper­i­ments in cog­ni­tive psy­chol­o­gy elo­quent­ly illus­trate the cru­cial role of cog­ni­tive inhi­bi­tion. One of the most famous par­a­digms in this field is the Stroop test. In this test, the sub­ject is pre­sent­ed with words denot­ing colours, such as “red” or “green”, but print­ed in a dif­fer­ent ink, for exam­ple, the word “red” writ­ten in blue. The chal­lenge is to name the colour of the ink rather than read the word, a task that cre­ates a direct con­fronta­tion between auto­mat­ic read­ing, gov­erned by Sys­tem 1, and vol­un­tary nam­ing, orches­trat­ed by Sys­tem 2. Suc­cess­ful­ly com­plet­ing this task requires acute inhibito­ry capac­i­ty, enabling the sub­ject to resist the instinc­tive urge to read the let­ters rather than the colour.

Anoth­er illu­mi­nat­ing exam­ple can be found in the field of cog­ni­tive bias­es, such as con­fir­ma­tion bias. Nat­u­ral­ly, our Sys­tem 1 tends to seek evi­dence that cor­rob­o­rates our pre-estab­lished beliefs. We must there­fore devel­op con­stant vig­i­lance and a strong inhibito­ry effort to think against our­selves, to chal­lenge our ini­tial intu­itions and embrace a more thought­ful and slow­er crit­i­cal approach, guid­ed by Sys­tem 2. In chil­dren, whose exec­u­tive func­tions are still devel­op­ing, or in old­er peo­ple, where frontal inhi­bi­tion tends to weak­en, the dif­fi­cul­ty in inhibit­ing auto­mat­ic respons­es is often more pro­nounced. This illus­trates, inci­den­tal­ly, that frontal inhi­bi­tion is not an innate skill but a cog­ni­tive fac­ul­ty that is acquired over time but can also decline with age.

How­ev­er, the role of frontal inhi­bi­tion goes far beyond sim­ply cor­rect­ing errors. It is cen­tral to ratio­nal deci­sion-mak­ing. The abil­i­ty to sus­pend hasty judge­ments, ques­tion one’s cer­tain­ties and analyse a sit­u­a­tion from var­i­ous angles relies on the inten­tion­al with­draw­al of Sys­tem 1 through inhibito­ry action. Recent stud­ies have shown that indi­vid­u­als who excel in log­i­cal rea­son­ing or cog­ni­tive reflec­tion tests do not nec­es­sar­i­ly have above-aver­age IQs, but are rather adept at con­tain­ing their erro­neous intu­itions. Ratio­nal­i­ty there­fore does not stem sole­ly from raw intel­li­gence, but from a refined mas­tery of the activ­i­ty of the frontal lobes.

Final­ly, prac­tices such as crit­i­cal think­ing and mind­ful­ness can strength­en this inhibito­ry capac­i­ty by teach­ing us to observe our thoughts with­out imme­di­ate­ly suc­cumb­ing to them. These approach­es show that inhi­bi­tion is not just an innate qual­i­ty, but a skill that can be cul­ti­vat­ed and refined through expe­ri­ence and train­ing to dis­tance our­selves from our own rapid thoughts.

The sub­tle mech­a­nism of frontal inhi­bi­tion is not immune to vul­ner­a­bil­i­ty. Acti­vat­ing it requires effort, because call­ing on Sys­tem 2is like climb­ing the steep slopes of slow think­ing – a demand­ing, ener­gy-inten­sive endeav­our that mobilis­es our most pre­cious resources: sus­tained atten­tion, work­ing mem­o­ry and inner vig­i­lance. But let a breath of fatigue cloud men­tal clar­i­ty, let stress creep in, or let the tumult of thoughts over­flow the dykes of our con­cen­tra­tion, and this fac­ul­ty is shak­en. Inhi­bi­tion fal­ters, los­es ground, and into this breach rush­es Sys­tem 1 once again, with its mis­lead­ing short­cuts and sweet-talk­ing automa­tisms, ready to take back con­trol of our thoughts.

Cer­tain con­di­tions, such as atten­tion deficit hyper­ac­tiv­i­ty dis­or­der (ADHD), schiz­o­phre­nia, or cer­tain frontal lobe syn­dromes, can dras­ti­cal­ly com­pro­mise this abil­i­ty to inhib­it. The result is increased impul­siv­i­ty, marked dif­fi­cul­ties in con­cen­trat­ing, and a propen­si­ty to give in to auto­mat­ic respons­es. In addi­tion, lifestyle fac­tors such as alco­hol, lack of sleep, and the use of cer­tain drugs or med­ica­tions also under­mine this inhibito­ry process.

In the most dra­mat­ic cas­es, where the frontal lobes are destroyed, the con­se­quences for behav­iour, cog­ni­tion and per­son­al­i­ty can be pro­found and some­times dis­as­trous. We are remind­ed of this inevitable fate by the trag­ic sto­ry of Phineas Gage, a rail­way fore­man in the Unit­ed States. In 1848, dur­ing a rou­tine blast­ing oper­a­tion, a fate­ful spark trig­gered an explo­sion, pro­pelling a piece of iron – one metre long, three cen­time­tres wide and weigh­ing six kilo­grams – through his skull. The object pierced his left cheek and passed through the base of his skull, tear­ing away his left frontal lobe. Incred­i­bly, Gage sur­vived the cat­a­clysm, even remain­ing con­scious for sev­er­al min­utes after the acci­dent. Although he recov­ered phys­i­cal­ly a few months after the acci­dent, those around him noticed pro­found and irre­versible changes in his per­son­al­i­ty. The man who had once been a mod­el of respon­si­bil­i­ty, reli­a­bil­i­ty and socia­bil­i­ty had giv­en way to an impul­sive, angry indi­vid­ual with no restraint or man­ners, unable to hold down a steady job or even main­tain a roman­tic rela­tion­ship. Phineas Gage end­ed up trav­el­ling across the Unit­ed States as a macabre curios­i­ty, dis­play­ing his injuries and exhibit­ing, as part of the Bar­num cir­cus, the famous crow­bar that had so bru­tal­ly rede­fined his exis­tence. This poignant sto­ry res­onates through the ages, remind­ing us of the com­plex­i­ty and fragili­ty inher­ent in the nature of Homo sapi­ens.

The mere exis­tence of an inhibito­ry mech­a­nism at the heart of the men­tal struc­ture is one of the most sub­tle gems of our cog­ni­tive archi­tec­ture – a silent but essen­tial piv­ot on which the frag­ile bal­ance of our think­ing human­i­ty rests. Like an inter­nal con­duc­tor, this inhibito­ry sys­tem mod­u­lates the dia­logue between Sys­tems 1 and 2, tem­per­ing impul­sive urges to give delib­er­ate thought the space it needs to flour­ish. Far from being a sim­ple brake, inhi­bi­tion reveals itself as the sub­tle lever that lifts the mind to the heights of crit­i­cal con­scious­ness, lucid­i­ty, and enlight­ened rea­son. This fac­ul­ty is the source of the moral respon­si­bil­i­ty of free human beings. As Albert Camus said, “A man is what he pre­vents him­self from becom­ing,” remind­ing us that human dig­ni­ty lies in the abil­i­ty to restrain one­self, to not give in to one’s instincts or impuls­es, even when one has the pow­er to do so!