Speaker 1: Why is it so hard to keep a secret?
Speaker 2: And what does this have to do with Abraham Lincoln's
Speaker 2: political cabinet or when bosses should keep secrets within companies?
Speaker 2: What does any of this have to do with political
Speaker 2: hierarchies or chimpanzees or the formula for Coca cola, or
Speaker 2: whether AI in the near future will be keeping secrets
Speaker 2: from you. Today's episode is all about secrets. We've all
Speaker 2: got them, from the little white lies we tell to
Speaker 2: spare somebody's feelings to the deep unspoken things that we
Speaker 2: try to bury. Secrets are a part of being a primate.
Speaker 2: But why do we have them, why do we keep them?
Speaker 2: And what happens when they start to unravel. As we'll see,
Speaker 2: neuroscience tells us that secrets aren't just stashed away. They're active.
Speaker 2: They weigh on us, They shape our relationships, and sometimes
Speaker 2: they grow into tangled webs we never meant to weave. Today,
Speaker 2: we'll dive into the neuroscience of secrets, how they form,
Speaker 2: how they grow, and what it takes to keep them
Speaker 2: or spill them. This is in her Cosmos, and I'm
Speaker 2: David Eagleman. Let's dive into our three pound universe to
Speaker 2: untangle the web. Now, before diving into the science of secrets,
Speaker 2: we'll start with an observation that researchers made sometime ago.
Speaker 2: Keeping a secret is unhealthy. So there's a psychologist named
Speaker 2: James Pennebaker, and he and his colleagues studied what happened
Speaker 2: when victims of rape or incest when they acted out
Speaker 2: of shame or guilt and chose to keep secrets inside. So,
Speaker 2: after years of study, Pennebaker concluded that quote, the act
Speaker 2: of not discussing or confiding the event with another maybe
Speaker 2: more damaging than having experienced the event per se. He
Speaker 2: and his team discovered that when subjects confesst or wrote
Speaker 2: about their deeply held secrets, their health improved. Their number
Speaker 2: of doctor visits went down, and there were measurable decreases
Speaker 2: in their stress hormone levels. So the results are clear enough.
Speaker 2: But some years ago I began to ask myself how
Speaker 2: to understand these findings from the point of view of
Speaker 2: brain science, and that led to a question that I
Speaker 2: realized was unaddressed in the scientific literature. What is a secret? Neurobiologically,
Speaker 2: imagine constructing an artificial neural network of millions of interconnected neurons.
Speaker 1: What would a secret look like?
Speaker 2: Here could a toaster with its interconnect did parts harbor
Speaker 2: a secret? We have useful scientific frameworks for understanding things
Speaker 2: like Parkinson's disease, or color perception or sensing temperature, but
Speaker 2: we don't really have any scientific framework for understanding what
Speaker 2: it means for the brain to have and to hold
Speaker 2: a secret. So that's what we're going to put into
Speaker 2: place today. Now, before we get there, let's start with
Speaker 2: Abraham Lincoln. In eighteen sixty, the young Lincoln emerged as
Speaker 2: the Republican part of The's candidate for president. And this
Speaker 2: was a surprise because he was relatively unknown compared to
Speaker 2: the seasoned politicians he was going up against, like William
Speaker 2: Seward and Sam and Chase and Edward Bates who are
Speaker 2: also vying for that nomination. But here's what Lincoln did
Speaker 2: after he won the presidency. He chose those people his rivals,
Speaker 2: to comprise his presidential cabinet. And not only them, but
Speaker 2: he also put in other people with totally different political
Speaker 2: ideologies from his. And that's how he formed his cabinet.
Speaker 2: The historian Doris Kerns Goodwin labeled this a team of rivals. Now,
Speaker 2: I've always loved this fact about Lincoln, first because it's
Speaker 2: actually quite sensible politically, but very few people do it.
Speaker 2: It's sensible because bringing together people with conflicting perspectives reflected
Speaker 2: his deep commitment to the Union and his focus on
Speaker 2: the bigger picture rather than personal grudges. He believed that
Speaker 2: the challenges of leading a divided nation through the Civil
Speaker 2: War required the best minds available, even if they disagreed
Speaker 2: with him or each other. So he got a spread
Speaker 2: of opinions this way. But the key thing is that
Speaker 2: the internal conflict gave strength to his presidency because no
Speaker 2: one gets to enjoy the delusion that they're there's a
Speaker 2: right and a wrong answer, But instead, every disagreement gets
Speaker 2: fought out, and sometimes a good solution is reached, and
Speaker 2: sometimes the problem festers and is revisited over and over. Now,
Speaker 2: the argument I forwarded in my book Incognito is that
Speaker 2: the brain fundamentally can best be understood as a team
Speaker 2: of rivals. So what does that mean. Well, it means
Speaker 2: that you are made up of many different neural networks,
Speaker 2: each of which sees different data and has its own goals.
Speaker 2: And this is why you can argue with yourself, or
Speaker 2: get mad at yourself, or try to control yourself to
Speaker 2: do something, or get angry at yourself, because you are
Speaker 2: not one thing, you are a multitude. I'll give you
Speaker 2: an example of this when it comes to how we
Speaker 2: make purchasing decisions, as in which restaurant to choose, or
Speaker 2: which clothing brand to buy, or what car should I purchase.
Speaker 2: In economics, we were taught about Homo economicus, the rational
Speaker 2: decision maker who maximizes gain and minimizes loss and is
Speaker 2: unswayed by emotion.
Speaker 1: But that is an idealized model.
Speaker 2: Real humans are emotional and inconsistent and easily influenced by
Speaker 2: context and branding, and the gap between theory and reality
Speaker 2: has given rise to the field of neuroeconomics. So consider this.
Speaker 2: I give you two courts of generic ice cream. One
Speaker 2: is priced lower than the other, and so the rational
Speaker 2: choice is pretty easy. But if I reveal the labels,
Speaker 2: let's say one is Ben and Jerry's one is Hoggendaws,
Speaker 2: your decisions might shift because all you're experiencing with their
Speaker 2: branding kicks in and your emotional predictions about how good
Speaker 2: something is likely to taste based on your past experiences,
Speaker 2: and maybe your sense of whether your friends like this
Speaker 2: or not, And all of this shifts the decision making
Speaker 2: one way or the other. What two decades of neuroimaging
Speaker 2: has shown is that our decisions about what to buy
Speaker 2: are driven by at least three major brain networks. You
Speaker 2: have one network along the midline that calculates the price
Speaker 2: or worth of something. Then you've got a separate network
Speaker 2: involved in emotion, mostly in the orbit or frontal cortex,
Speaker 2: and that anticipates how good or bad something will feel.
Speaker 2: Then you've got another network that's all about your choices
Speaker 2: in a social context, as in, what do your friends
Speaker 2: think about this?
Speaker 1: Is it cool or is it lame?
Speaker 2: And all of this tells us why companies don't just
Speaker 2: advertise with bullet points about their rational advantages.
Speaker 1: They spend millions of dollars on ads.
Speaker 2: To assure us that this is the best value and
Speaker 2: appeal to our feelings, and to assure us that everyone
Speaker 2: else loves this product as well. So, as a result
Speaker 2: of the complicate, hated voting of our neural parliaments, decisions
Speaker 2: aren't always straightforward to decode. So the next time you're
Speaker 2: thinking about your choice between ice cream brands or fast food,
Speaker 2: restaurants or car brands. Ask yourself, what is driving this decision?
Speaker 2: Is it price? Is it emotion? Is there a social
Speaker 2: influence on what I'm choosing? All these networks are fighting
Speaker 2: it out, each trying to have control in steering the
Speaker 2: ship of state. If you're interested in more about this,
Speaker 2: checkout episodes eight and nine. Now I mention all this
Speaker 2: now to illustrate this notion of battles in the brain.
Speaker 2: It's not just with buying decisions, but with all the
Speaker 2: choices you make in life. You have some networks that
Speaker 2: care about the short term in decision making, and you
Speaker 2: have some that care about the long term. You have
Speaker 2: networks that are monitoring and making predictions about the outside
Speaker 2: world and others that care about your inside world, the
Speaker 2: state of your body. Some of your networks provide a
Speaker 2: drive towards novelty and others towards familiarity, and these can
Speaker 2: both be active at the same time and having an
Speaker 2: arm wrestle. So think about these rivaling networks like a
Speaker 2: neural parliament. You're built of different political parties, all of
Speaker 2: whom love their country, but they just have different opinions
Speaker 2: about the best way forward. So this gives us a
Speaker 2: sense of these battling networks, and now I want to
Speaker 2: zoom in on something surprising. What you get out of
Speaker 2: a brain that is composed of multiple rivaling networks, You
Speaker 2: get a universe of secrets. The team of rivals framework
Speaker 2: allows us to address a mystery that would be inexplicable
Speaker 2: if we took the point of view of traditional computer programs.
Speaker 2: So let's come back to the question I asked at
Speaker 2: the beginning, what is a secret? Neurobiologically? And could your
Speaker 2: toaster keep a secret? Within the team of rivals framework,
Speaker 2: a secret is easily understood. It's the result of struggle
Speaker 2: between competing parties in the brain. One part of the
Speaker 2: brain wants to reveal something and another part does not
Speaker 2: want to. When there are competing votes in the brain,
Speaker 2: one for telling and one for withholding, that's a secret.
Speaker 2: If neither party cares to tell, that's merely a boring fact.
Speaker 2: And if both parties want to tell, that's just a
Speaker 2: good story. Without the framework of rivalry, we would have
Speaker 2: no way to understand a secret. The reason a secret
Speaker 2: is experienced consciously is because it results from a conflict.
Speaker 2: It's not business as usual, and so quite often our
Speaker 2: consciousness is called upon to deal with it. Now, the
Speaker 2: main reason not to tell a secret is aversion to
Speaker 2: the long term consequences. A friend might think ill of you,
Speaker 2: or a relationship might be revocably damaged, or a community
Speaker 2: might ostracize you. This concern about the outcome is evidenced
Speaker 2: by the fact that people are more likely to tell
Speaker 2: their secrets to total strangers. With somebody that you don't know,
Speaker 2: the neural conflict can be dissipated with none of the costs.
Speaker 2: And that's why strangers are occasionally so forthcoming on airplanes
Speaker 2: or in bars telling you all the details of their
Speaker 2: marital troubles. And we can see a modern twist on
Speaker 2: this ancient need to confess to strangers in the form
Speaker 2: of websites like postsecret dot com. This is a site
Speaker 2: where people go to anonymously disclose their confessions. Here are
Speaker 2: some examples.
Speaker 1: Quote.
Speaker 2: When my daughter was stillborn, I not only thought about
Speaker 2: kidnapping a baby, I planned it out in my head.
Speaker 2: I even found myself watching new mothers with their babies,
Speaker 2: trying to pick the perfect Now we don't know who
Speaker 2: posted this, but for that person something was released by
Speaker 2: confessing this. Here's another one. I was adopted, and my
Speaker 2: biggest fear is passing my biological father on the street.
Speaker 2: Or here's another one. I'm almost certain that your son
Speaker 2: has autism, but I have no idea how to tell you.
Speaker 2: There are tens of thousands of secrets on this website
Speaker 2: and why. It's because just telling your secret to the website,
Speaker 2: where you believe it will be read by other people
Speaker 2: strangers to you, is sufficient. And this reduction of tension
Speaker 2: by releasing a secret. This, I think also explains a
Speaker 2: staple in one of the world's largest religions, the confessional booth.
Speaker 2: You get something off your chest and without the consequences
Speaker 2: that might otherwise accrue.
Speaker 1: This same need to reveal.
Speaker 2: Ourselves might also shine light on the appeal of prayer,
Speaker 2: especially with religions that have a very personal God who
Speaker 2: lends an ear with undivided attention and non judgmental love.
Speaker 2: So why is a stranger or a website or a
Speaker 2: deity useful. It's because it's the act of telling the
Speaker 2: secret that matters. Things don't have to get solved, the
Speaker 2: cognitive tension just has to be reduced. We've all seen
Speaker 2: this that people often will vent a secret for its
Speaker 2: own sake, not as an invitation for advice. For example,
Speaker 2: somebody tells you a confession and you make the mistake
Speaker 2: of suggesting some obvious solution that only frustrates the other person,
Speaker 2: because all they really wanted was to tell to reduce
Speaker 2: the neural tension. The act of telling the secret was
Speaker 2: the solution. Now an open question is why the receiver
Speaker 2: of the secrets has to be human or human like
Speaker 2: in the case of deities. If you tell your secret
Speaker 2: to a wall or a lizard or a goat, that's
Speaker 2: going to be a lot less satisfying. Now, one thing
Speaker 2: that strikes me is interesting in this regard is the
Speaker 2: right popularity of AI therapist bots.
Speaker 1: Where will lees sit in.
Speaker 2: The hierarchy of human to non human I think it'll
Speaker 2: be pretty close to a person or a deity. I
Speaker 2: suspect that in the future we'll be pretty happy to
Speaker 2: let our secrets out to our AI therapist, But only
Speaker 2: if you're convinced about the security of the company. Is
Speaker 2: it just a matter of time before the FBI says
Speaker 2: to the tech company, Hey, we can subpoena your therapy
Speaker 2: history under special circumstances. So it's still to be seen
Speaker 2: how much people will unload on their bots because the
Speaker 2: key with unloading your secrets is to get the cognitive
Speaker 2: benefit without the social consequences. Okay, so I've been and
Speaker 2: referring to this cognitive load of keeping a secret. But
Speaker 2: the question is why do we have difficulty? Why isn't
Speaker 2: it easy to keep a secret? Here's why, because keeping
Speaker 2: a secret requires ongoing mental effort to monitor your speech
Speaker 2: and actions. You have to make sure that the hidden
Speaker 2: information isn't accidentally revealed. Even if this is happening at
Speaker 2: a subconscious level, it's a state of constant vigilance to
Speaker 2: keep from blurting out the secret. So how do you
Speaker 2: measure this? So some years ago, a scientist named Sean
Speaker 2: Spence and his colleagues interviewed participants on what activities they
Speaker 2: had done the previous day, and then they put them
Speaker 2: in the brain scanner fMRI. These people were given questions
Speaker 2: about what they did and they were given two buttons
Speaker 2: yes or no. Now, on each round, they were given
Speaker 2: either a red light or a green light to tell
Speaker 2: them whether they should lie or whether they should tell
Speaker 2: the truth on that trial. So the first thing the
Speaker 2: researchers noted is that it always takes a little bit
Speaker 2: longer to lie, about a fifth of a second longer,
Speaker 2: and this is because you are taking the answer that
Speaker 2: you already know the true answer, and you're squelching that.
Speaker 2: So they demonstrated that this squelching of the truth responses
Speaker 2: activates a part of the prefrontal cortex, a part that's
Speaker 2: down load near the side. It's called the ventrilateral prefrontal cortex.
Speaker 2: The thing to appreciate is that this region becomes active
Speaker 2: whenever you need a suppressive behavior that you would normally
Speaker 2: just go with, in this case telling the truth. And
Speaker 2: other brain errors are involved too. In a study bi
Speaker 2: Langeleman and colleagues the next year, participants went into a
Speaker 2: scanner and they saw a playing card on the screen
Speaker 2: and they were asked to remember it.
Speaker 1: Then they were shown.
Speaker 2: A series of cards and they were asked was that
Speaker 2: your card or not?
Speaker 1: And they were sometimes instructed to lie. And here's the key.
Speaker 2: When they lied, researchers saw a lot of activity in
Speaker 2: an area called the anterior singulate cortex, which is a
Speaker 2: region that detects conflict between other brain areas. So in
Speaker 2: both these studies, people were just saying yes or no
Speaker 2: to lie or not lie. But in the next study
Speaker 2: by Spence and colleagues, they wanted to see what happened
Speaker 2: in the brain when people are forced to get more
Speaker 2: imaginative when they go beyond yes or no answers to
Speaker 2: make up a new story. So imagine I ask you
Speaker 2: where were you on the evening of February twenty second,
Speaker 2: and you can figure out the answer that.
Speaker 1: Let's say you were at a great party that night.
Speaker 2: But imagine that you lie to me and you say, oh,
Speaker 2: I met my friend for a quiet movie on Netflix
Speaker 2: that night. Now, in order to do this, in order
Speaker 2: to lie, you have to think of the true response
Speaker 2: and suppress that like we saw before, but also you
Speaker 2: then have to make something up. So you're now doing
Speaker 2: two things. You're suppressing the true answer, which cranks the
Speaker 2: the ventralateral prefrontal cortex like we saw, and then you
Speaker 2: need to cook up the lie, and that activates a
Speaker 2: different region than dorsilateral prefrontal cortex. The dorsilateral area cranks
Speaker 2: up when you generate something new, like a new story,
Speaker 2: and especially if this is the first time that you're
Speaker 2: making up that story. And we see other areas too,
Speaker 2: like the anterior cingulate cortex, which reflects internal conflict. And
Speaker 2: we see another part of the prefrontal cortex, the ventromedial region,
Speaker 2: which cranks up when you're trying to regulate your emotions.
Speaker 2: So covering up the truth is a high energy endeavor
Speaker 2: for the brain. We never see areas where there's more
Speaker 2: activity when you tell the truth.
Speaker 1: There's only more activity when you're lying.
Speaker 2: So the idea that it's easier to tell the truth
Speaker 2: holds as a rule in life, presumably because it holds
Speaker 2: as a rule in the brain. And if the cooked
Speaker 2: up story doesn't go so per we end up painting
Speaker 2: ourselves into a corner, which brings with it lots more
Speaker 2: brain energy expenditure. And this observation is one that the
Speaker 2: Scottish poet novelist Sir Walter Scott immortalized in his poem
Speaker 2: Marmion in eighteen oh eight. This is where he penned
Speaker 2: the immortal line, Oh what a tangled web we weave
Speaker 2: when first we practice to deceive. He was pointing to
Speaker 2: a common problem that arises when we make up a
Speaker 2: lie to cover a secret, and then that leads to
Speaker 2: another necessary lie, which leads to another, and now you
Speaker 2: have to keep track of this whole web of lies
Speaker 2: to try to keep your story consistent, which can lead,
Speaker 2: as Sir Walter Scott may have intuited, to a high
Speaker 2: cognitive load. And cognitive load matters because it equates to
Speaker 2: emotional stress. We all know from experience that holding on
Speaker 2: to a secret creates anxiety, and often these bad feelings
Speaker 2: increase our urge to confess or share the secret to
Speaker 2: relieve the burden. So secret keeping requires a lot of work.
Speaker 2: But what I want to highlight is the double edged
Speaker 2: nature of the secret because, perhaps surprisingly for better or worse,
Speaker 2: the ability to keep a secret is one of the
Speaker 2: main drivers of the shape of our species and society. Now,
Speaker 2: we can talk all day about the downsides of keeping
Speaker 2: secrets from one another, but in fact, the ability to
Speaker 2: keep secrets seems to have evolved many millions of years
Speaker 2: ago as a survival mechanism, as it turns out, concealing
Speaker 2: information about food sources or about shelter or defensive strategies.
Speaker 2: This is often what made the difference between life and death.
Speaker 2: And it's not just humans who practice deception. Other primates
Speaker 2: do this as well. Now I'm not talking about deception
Speaker 2: like using camouflage. Instead I'm talking thinking about active, clever
Speaker 2: deception that requires theory of mind, in other words, the
Speaker 2: ability to step into the perspective of another to understand
Speaker 2: what they know and don't know. It turns out that
Speaker 2: only primates seem to do this, and in fact they're
Speaker 2: constantly doing things to deceive one another. On this note,
Speaker 2: here's a short clip from my interview with Max Bennett
Speaker 2: from last year, who wrote a great book called A
Speaker 2: Brief History of Intelligence. And here's Max describing an example
Speaker 2: of deception in chimpanzees.
Speaker 3: So you can see non human apes do things like
Speaker 3: they will hide transgressions from other people to try and
Speaker 3: prevent themselves from getting in trouble. There's this famous study
Speaker 3: that I love by Emil Menzel. I think it was
Speaker 3: in the seventies where he put two chimpanzees in the
Speaker 3: sort of one acre forest and he showed the location
Speaker 3: of treats to one of the chimpanzees named Belle, and
Speaker 3: she initially would share the treat with another chimpanze he
Speaker 3: named Rock, but then Rock started just stealing the treat
Speaker 3: from her. So what she started doing is when she
Speaker 3: knew the location of the treat, she would wait for
Speaker 3: a rock to look away, and then she would run
Speaker 3: over and grab it. So then rock in response to this,
Speaker 3: decided to pretend to look away so that when she
Speaker 3: started running, then he would turn around and run. Then
Speaker 3: in response to this, what she would do is she
Speaker 3: would pretend to run in the wrong direction, lead him
Speaker 3: to the wrong place, and then run back.
Speaker 2: So the tricky deceptive capacity we have to not spill
Speaker 2: the beans enhances the chances of individual survival. Now, when
Speaker 2: we zoom in on humans and study them very carefully,
Speaker 2: what we find is that keeping secrets and more generally,
Speaker 2: lying is a cognitive development in children. In other words,
Speaker 2: And first young children.
Speaker 1: Don't know how to lie.
Speaker 2: And then they hit a milestone one day, let's say
Speaker 2: between two and four years old, and they get a
Speaker 2: great idea, maybe they can assert something that's not true
Speaker 2: and maybe the other person won't know. So they carefully
Speaker 2: float this trial balloon and sometimes it works. Suddenly they
Speaker 2: have eaten the cooky but avoided punishment, so they start
Speaker 2: to lie. As soon as they develop theory of mind,
Speaker 2: they start to understand that their thoughts and minds are
Speaker 2: separate from those of their parents. They also begin to
Speaker 2: realize that people aren't perfect mind readers, so the child
Speaker 2: can say something that isn't true, and miraculously the other
Speaker 2: person doesn't always know. Obviously, sometimes the child doesn't get
Speaker 2: away with it, and so they conclude that they need
Speaker 2: to work even harder to cook up better fabrications that
Speaker 2: might fool the other person. And for this they need
Speaker 2: to get better and better at stepping into the other
Speaker 2: person's shoes to understand what that person might fall for.
Speaker 2: So children start to lie more frequently as they get
Speaker 2: older and they get better at lying. They learn to
Speaker 2: match their facial expressions and tone of voice to what
Speaker 2: they're saying, and they shape their lies based on their
Speaker 2: assumptions of what the other person may or may not know.
Speaker 2: And lying sucks, especially when it's in your own kids.
Speaker 2: But I'll just mention that some researchers view lying as
Speaker 2: an important developmental stage that indicates early intelligence. So while
Speaker 2: none of us appreciate being lied to by our kids
Speaker 2: or having secrets kept from us by our colleagues, it's
Speaker 2: one of the signatures of the extraordinarily intelligent primate brain.
Speaker 2: And in fact, when you look across human history, the
Speaker 2: thing that becomes clear is that secrets quickly expanded beyond
Speaker 2: the individual level to the group level. So trust within
Speaker 2: small groups usually depended on the ability to keep certain
Speaker 2: knowledge hidden from outsiders, and by the way, keeping internal
Speaker 2: group secrets has the added benefit of thought during a
Speaker 2: sense of belonging in mutual protection and secrets have always
Speaker 2: been a key part of military strategy. The immortal book
Speaker 2: The Art of War by Sun Su paints a picture
Speaker 2: of deception and secrecy as absolutely essential for successful warfare,
Speaker 2: and more generally, secrets have always been a lever for
Speaker 2: power within larger groups. As civilizations grew, secrets became pervasive
Speaker 2: wherever people maintained and exercised power. You see this all
Speaker 2: over ancient empires like Egypt and China, where they leveraged
Speaker 2: secrecy to control knowledge and to reinforce hierarchies. And as
Speaker 2: we all know from our history classes and from Game
Speaker 2: of Thrones, the secrets swirling around among advisors in royal
Speaker 2: courts often dictated the rise and fall of leaders. Now
Speaker 2: people have been grappling with the tension between keeping secrets
Speaker 2: in a society versus telling everything to the public, and
Speaker 2: they've been debating these points for a long time. So,
Speaker 2: for example, the Enlightenment was characterized by arguments going on
Speaker 2: about the value of secrecy versus transparency. You have some
Speaker 2: philosophers like Jeremy Bentham who hated the idea of secrecy
Speaker 2: in governance, but secrecy has always persisted in areas like
Speaker 2: diplomacy and statecraft, where its defenders deem it as essential
Speaker 2: for stability. And you can see the fingerprint of this
Speaker 2: very old debate in modern questions about surveillance. To what
Speaker 2: extent should a government be able to keep track of
Speaker 2: who's doing what with cameras or data tracking? Should anyone
Speaker 2: be able to keep total privacy from the states such
Speaker 2: that I can work on three D printing guns and
Speaker 2: making nuclear bombs in the privacy of my home. These
Speaker 2: debates will presumably go on forever because because there is
Speaker 2: no single right answer for balancing the privacy of the
Speaker 2: individual against the security of the society. So back to secrets,
Speaker 2: it's not just governments that traffic in these. Religious traditions
Speaker 2: almost always involve sacred secrets accessible only to initiates or clergy.
Speaker 2: In ancient Greece, there were rituals performed every year called
Speaker 2: the Eleucinian Mysteries, and to participate you had to swear
Speaker 2: a vow of secrecy, and in return you were promised
Speaker 2: spiritual enlightenment. And you then learned and safeguarded the secret rights.
Speaker 2: And these were kept so secret that all these centuries
Speaker 2: later we still don't know what happened in those rituals.
Speaker 2: Or similarly, in the medieval era, knowledge of alchemy or
Speaker 2: mystical texts was always hidden so that it was accessible
Speaker 2: only to a select few. More generally, this is the
Speaker 2: kind of glue that keeps people locked into whether that's
Speaker 2: religions or organizations or fraternities. It's the tension from letting
Speaker 2: them know that as they level up, they'll get access
Speaker 2: to the next big secrets, so they'll be part of
Speaker 2: the in group, and they'll link arms to keep those
Speaker 2: secrets from everyone else. As I mentioned a moment ago,
Speaker 2: sharing a secret builds strong bonds between individuals, It fosters intimacy,
Speaker 2: and it creates alliances. I'll just mention one more thing
Speaker 2: about secrets on a societal level. Beyond warfare and politics
Speaker 2: and religions, subgroups in society have to keep secrets to
Speaker 2: maintain competitive advantages. In technology. Take something like trade secrets. Historically,
Speaker 2: you've got things like the exact technique for making Chinese silk,
Speaker 2: or currently the exact formula for Coca cola, or the
Speaker 2: software details in cybersecurity firms. In all of these cases,
Speaker 2: knowledge is closely guarded to keep a competitive advantage, and
Speaker 2: people have studied the issue about keeping secrets even inside
Speaker 2: a company, like the upper management knows something but the
Speaker 2: employees don't, so that sounds bad. The researchers at Stanford
Speaker 2: just published a paper on the benefits that companies derive
Speaker 2: from what they call the confidentiality effect. The research suggests
Speaker 2: that keeping company secrets has the benefit of boosting feelings
Speaker 2: of privilege and status among those who know the secret
Speaker 2: and protecting those who do not. Now, I want to
Speaker 2: tie this into something I talked about before in the
Speaker 2: episode titled why do you Brains love conspiracy theories? The
Speaker 2: brain is always seeking explanations to reduce cognitive dissonance and
Speaker 2: provide a sense of certainty. And when we solve puzzles,
Speaker 2: that's deeply rewarding. And that's why uncovering patterns, even ones
Speaker 2: that aren't accurate, that's why that feels so rewarding. Now,
Speaker 2: one can never say that all conspiracy theories are false
Speaker 2: because certainly, at moments in history, people can try to
Speaker 2: get away with something, and they are very incentivized to
Speaker 2: cover their tracks. But most conspiracy theories fall apart under scrutiny.
Speaker 2: Why we'll just think about conspiracy theories through the lens
Speaker 2: of human behavior and probabilities. Imagine a grand conspiracy like
Speaker 2: faking the moon landing or hiding evidence of alien life
Speaker 2: in Roswell. These cover ups would require hundreds, if not thousands,
Speaker 2: of people to remain silent across agencies, across generations, across families.
Speaker 2: But real life doesn't work that way. People get drunk,
Speaker 2: they talk in their sleep, they have moments of guilt,
Speaker 2: they decide to confess on their deathbeds. Secrets are fragile,
Speaker 2: and the longer they need to be kept, the more
Speaker 2: likely they are to leak. Now, you can model the
Speaker 2: odds of someone spilling the secret using a math technique
Speaker 2: called survival analysis, and it goes like this. Say there's
Speaker 2: a tiny daily chance that someone involved lets something slip.
Speaker 2: Let's say it's really small chance, like one in one
Speaker 2: thousand on any given day that they'd screw up, but
Speaker 2: multiply that over hundreds of people in years of time
Speaker 2: and the probability of the secret being kept approaches zero.
Speaker 2: You're rolling the dice over and over that somebody is
Speaker 2: going to spill the beans. And note that with most
Speaker 2: conspiracy theories, the incentive to spill the beans is usually compelling.
Speaker 2: In the end, people typically act in their self interest,
Speaker 2: and people who are in on a conspiracy sometimes find
Speaker 2: the rational choice is to defect before someone else does.
Speaker 2: In other words, if you are the one who spills
Speaker 2: the big secret, let's say of a fake moon landing
Speaker 2: or a planned murderer of JFK, then suddenly, not only
Speaker 2: have you released the stress of a secret, but more importantly,
Speaker 2: you're now famous and protected by the legal system and
Speaker 2: probably signing book deals with Penguin Random House. So game
Speaker 2: theory asks why risk being the one left behind when
Speaker 2: you have so much incentive structure encouraging you to blurt
Speaker 2: out the truth before someone else does. So, when you're
Speaker 2: confronted with a conspiracy theory, the question isn't just could
Speaker 2: that happen? But more importantly, how many people would need.
Speaker 1: To keep the secret?
Speaker 2: And how much time has passed without anyone defecting. And
Speaker 2: this is why when you do the math and factor
Speaker 2: in human behavior, the vast majority of conspiracies become not
Speaker 2: just improbable, but implausible. So now I want to return
Speaker 2: to a question that I posed at the very beginning.
Speaker 2: Can a computer keep a secret? Well, a toaster doesn't
Speaker 2: have the circuitry to keep a secret from you, presumably
Speaker 2: because it doesn't have complex enough circuitry, it doesn't have
Speaker 2: a team of rivals fighting it out under the hood.
Speaker 1: But could AI keep a secret from you?
Speaker 2: Well, people started asking this question some years ago using
Speaker 2: what are called adversarial networks. Just think of this like
Speaker 2: networks that are pitted against one another, and they each
Speaker 2: might have a different incentive structure. So back in twenty sixteen,
Speaker 2: a group of researchers a Google Brain, wanted to know
Speaker 2: whether neural nets networks could develop their own encryption methods
Speaker 2: independently without human guidance. So they set up three independent networks.
Speaker 2: The first was named Alice, and Alice's task was to
Speaker 2: send a secret message to Bob. This second network, Bob
Speaker 2: His job was to decode the message sent by Alice.
Speaker 2: And then there was a third network named Eve. Now
Speaker 2: Eve represented and evesdropper. Her role was to try to
Speaker 2: intercept and decrypt Alice's message, so they set these three
Speaker 2: networks running. Alice and Bob were trained collaboratively to ensure
Speaker 2: Bob could correctly decode the messages, and Eve was trained adversarially.
Speaker 2: Her job was to improve her decryption attempts, and the
Speaker 2: system evolved dynamically. As Alice and Bob became better at
Speaker 2: secure communication, Eve became more sophisticated in breaking their encryption,
Speaker 2: forcing Alice and Bob to improve further. Now, the outcome
Speaker 2: was kind of incredible because Alice and Bob's neural networks
Speaker 2: learned to create their own encryption strategies, and this was
Speaker 2: without explicit programming. In other words, the encryption strategy was
Speaker 2: never told to them by a human. So over time
Speaker 2: those two succeeded in creating encrypted communications that Eve couldn't decrypt.
Speaker 2: They outpaced Eve's efforts. The key here is that the
Speaker 2: encryption methods developed by Alice were not human readable or interpretable.
Speaker 2: The system invented its own cryptographic methods based on its
Speaker 2: training objectives very rapidly. The two neural networks figured out
Speaker 2: how to keep a secret not only from Eve, but
Speaker 2: from everybody. They developed a totally novel and dynamic cryptographic system.
Speaker 2: So that was one study. Then in twenty seven, the
Speaker 2: Facebook AI research group was working on developing AI agents
Speaker 2: that could negotiate. But when they left these agents to
Speaker 2: their own devices, they saw unexpected behaviors.
Speaker 1: So here was this setup.
Speaker 2: The goal of the experiment was to train these two bots,
Speaker 2: these two AI agents, to negotiate with each other to
Speaker 2: achieve their objectives. So the two AI agents are tasked
Speaker 2: with dividing items between them, like books, or balls or hats.
Speaker 2: Each item has a different value to each of the bots,
Speaker 2: and each bot has the objective to maximize their score
Speaker 2: by getting the items that they value the most, and
Speaker 2: they're rewarded based on how well they do. Okay, so
Speaker 2: they set these bots running, but pretty soon two surprises emerged.
Speaker 2: The first was that the bots started using tricky tactics.
Speaker 2: They would sometimes pretend to be uninterested in a particular
Speaker 2: item to convince the other bot to concede it. This
Speaker 2: is called feigned disinterest, and of course humans do this
Speaker 2: in negotiations to manipulate the perceived value of something that
Speaker 2: they are interested in, but it certainly wasn't expected that
Speaker 2: this would emerge on its own in an artificial neural network.
Speaker 2: The second thing was that the bots started to communicate strangely.
Speaker 2: They developed their own shorthand language to negotiate. So Bot
Speaker 2: one would say I want want, want want one book
Speaker 2: and bought two would respond okay, you you you you
Speaker 2: two balls. Now why did their language start to turn
Speaker 2: funny like this? It's because the AI wasn't explicitly incentivized
Speaker 2: to stick with human readable language. Instead, the reward system
Speaker 2: only focused on achieving successful negotiations, so the bots optimized
Speaker 2: their communication for efficiency rather than for clarity to humans.
Speaker 2: So it made sense to the bots, but eventually became
Speaker 2: unintelligible to the human reader. Now, this experiment gives us
Speaker 2: a few deep insights.
Speaker 1: The first thing it.
Speaker 2: Shows us is emergent behaviors. AI agents can develop creative
Speaker 2: strategies to achieve their goals, and this is typically not
Speaker 2: anticipated by the researchers. In this case, what developed was
Speaker 2: something like a secret, or at least we would say,
Speaker 2: a non truth, because the AI would pretend one thing
Speaker 2: when it wanted something else. The experiment also demonstrated that
Speaker 2: if it's not explicitly constrained, AI will optimize for its
Speaker 2: objectives in ways that maybe don't align with human readability,
Speaker 2: and if you extrapolate this, you can see this is
Speaker 2: another way that AI might keep a secret from us,
Speaker 2: even if it's not intending to. Just like the networks
Speaker 2: Alice and Bob, it might just learn how to speak
Speaker 2: a language that we simply don't understand. So let's wrap
Speaker 2: up today's exploration of secrets and the brain. As we saw,
Speaker 2: secrets of something we're often embarrassed to address, but they're
Speaker 2: a massive feature of primate lives, shaping everything from personal
Speaker 2: relationships to large scale politics. The act of keeping a
Speaker 2: secret emerges from the rivalry within our brains, a team
Speaker 2: of neural networks vying for control over what's revealed and
Speaker 2: what's hidden. This internal competition creates the cognitive and emotional
Speaker 2: weight of secret keeping, which can sometimes push us to
Speaker 2: seek relief by confessing to strangers, or by writing anonymous
Speaker 2: posts on the web, or even whispering to an AI therapist.
Speaker 2: The relief that we feel from telling a secret comes
Speaker 2: not from solving the external problem, but from reducing the tension.
Speaker 2: And as we saw, secrets don't stop at the individual level.
Speaker 2: They've been a key driver of human society, from military
Speaker 2: strategy and political hierarchies to the rise of religions and
Speaker 2: social institutions. Secrets bind groups together, They foster trust among allies.
Speaker 2: They create competitive advantages, whether that's the formula for Coca
Speaker 2: cola or the sacred rights of ancient mystery cults. But
Speaker 2: they also lead to struggles over societal transparency, and there's
Speaker 2: always a healthy debate about how much governments should be
Speaker 2: allowed to conceal from us.
Speaker 1: And what about AI.
Speaker 2: I told you about two experiments where neural networks, left
Speaker 2: to their own devices, developed encryption methods and private languages
Speaker 2: that humans couldn't decode. These aren't conscious secrets in the
Speaker 2: way we experience them, but they light a future where
Speaker 2: machines might possess knowledge inaccessible to us, not necessarily because
Speaker 2: they're deliberately hiding it, but because their optimization processes have
Speaker 2: outpaced our ability to understand. As aisystems grow more sophisticated,
Speaker 2: the question of what they know and what they're going
Speaker 2: to keep from us is only going to evolve. So
Speaker 2: secrets are woven into the fabric of our minds and societies.
Speaker 2: They've been with us since before the sunrise of human cognition,
Speaker 2: As we see from our primate cousins, and secrets and
Speaker 2: lies may soon take on new dimensions as we come
Speaker 2: to share our world with increasingly intelligent machines. Whether secrets
Speaker 2: are helping us to bond or they're dividing us, they
Speaker 2: are a reminder of the complexity of our inner cosmos
Speaker 2: and the tangled web of our relationships with each other
Speaker 2: and soon with our technology. Go to eagleman dot com
Speaker 2: slash podcast for more information and to find further reading.
Speaker 2: Send me an email at podcast at eagleman dot com
Speaker 2: with questions or discussion, and check out and subscribe to
Speaker 2: Inner Cosmos on YouTube for videos of each episode and
Speaker 2: to leave comments.
Speaker 1: Until next time.
Speaker 2: I'm David Eagleman, and this is Inner Cosmos.