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 !