Bayesian Integration: Reality is Often Inaccurate

“Reality often is inac­cu­rate.” 
~Douglas Adams, The Hitchhiker’s Guide to the Galaxy

In 1995, a 29-year-old con­struc­tion work­er in England jumped off of some scaf­fold­ing and onto a plank on a build­ing site, land­ing on a 7‑inch nail. The nail pierced his boot, punch­ing through the sole and ful­ly out the top of the boot. The pain hit instant­ly, and the man start­ed scream­ing. He was rushed to the ER, where a sur­geon inject­ed him with mida­zo­lam. The man kept scream­ing in pain. Finally, the sur­geon admin­is­tered fen­tanyl, a seda­tive 100 times more potent than morphine. 

When the man had final­ly calmed down, the sur­geon removed the nail care­ful­ly from the boot and then took the man’s boot and sock off as well. That’s when the hos­pi­tal staff dis­cov­ered some­thing astound­ing. The nail had passed between his toes and hadn’t even scratched his skin! There was no dam­age what­so­ev­er to his foot, no blood, and no punc­ture wound.

And yet the man expe­ri­enced excru­ci­at­ing pain that was all too real. So what hap­pened? Basically, the man’s brain col­lect­ed what sen­so­ry infor­ma­tion was avail­able — he could lit­er­al­ly see the nail stick­ing out the top of his boot, as well as the hor­ri­fied looks on the faces of his fel­low con­struc­tion work­ers — and filled in the blanks, using con­text to deter­mine what hap­pened (you have been hurt) and how to respond (here is some excru­ci­at­ing pain. Get to a hos­pi­tal imme­di­ate­ly). 

The world is what we think it is and what we pre­dict it will be. So it might behoove us to slow down our thoughts and become more flex­i­ble with them.

The process of com­bin­ing pri­or knowl­edge with uncer­tain evi­dence is known as Bayesian inte­gra­tion. This phe­nom­e­non has a major impact on our per­cep­tions, thoughts, and actions. We take what we can sense and then fill in the blanks to cre­ate our real­i­ty. In fact, our expec­ta­tions so influ­ence our expe­ri­ences that our expec­ta­tions often become our experiences. 

What I’m say­ing is this. The world is what we think it is and what we pre­dict it will be. So it might behoove us to slow down our thoughts and become more flex­i­ble with them.

The con­struc­tion work­er thought he had plen­ty of  “evi­dence” to sup­port his belief that the nail had pen­e­trat­ed his foot. He couldn’t actu­al­ly see any dam­age to his foot, but his brain made a “best guess” as to how bad the injury was and respond­ed with pain. 

This reminds us to stay flex­i­ble in our thoughts and opin­ions, to remem­ber that what we “know” (both indi­vid­u­al­ly and col­lec­tive­ly) is dwarfed by what we don’t — and can­not — know. If we assume that our real­i­ty is, as Douglas Adams says, “often inac­cu­rate,” then our days should be lived with a more open-mind­ed per­spec­tive. Because a flex­i­ble mind is a pow­er­ful one. Flexible think­ing is imag­i­na­tive, intu­itive, insight­ful, and inves­tiga­tive; it improves the out­comes of Bayesian inte­gra­tion by cre­at­ing sev­er­al pos­si­ble sce­nar­ios instead of quick­ly jump­ing to a sin­gle con­clu­sion. Had the con­struc­tion work­er con­sid­ered there was more than one way to inter­pret the expe­ri­ence, he could have saved him­self a lot of pain.

We can all think of a time when our expec­ta­tions cre­at­ed more pain than was nec­es­sary. The bio­chem­i­cal lifes­pan of an emo­tion is only 90 sec­onds. Biochemical means the sen­sa­tions — like an adren­a­line rush, tight­ness in the throat, a rapid heart­beat, for exam­ple — arise, peak, and then dis­si­pate on their own in about 90 sec­onds. So pain and fear and joy and sur­prise? They are gen­er­al­ly metab­o­lized in the body in under two min­utes. So why does it feel like so much longer?

It’s the accom­pa­ny­ing nar­ra­tive we write that makes the emo­tion linger. The sto­ry we tell about the expe­ri­ence keeps it hang­ing around. Because humans are designed to think in sto­ries, we often tend to con­flate our body’s sig­nals as emo­tions, when in fact, they’re just bio­chem­i­cal process­es. They will pass — unless we attach a sto­ry to them and keep them alive. A flex­i­ble mind can more eas­i­ly iden­ti­fy an emo­tion sep­a­rate­ly from the sto­ries, opin­ions, and expe­ri­ences we tell about that emotion. 

So the next time you encounter a stress­ful expe­ri­ence? Slow down to let the emo­tion dis­si­pate. Then think of all the sto­ries that could be true. And while you’re at it, you might as well pick the most opti­mistic outcome.