The Diary Of A CEO with Steven Bartlett - Most Replayed Moment: The 4 Personalities Living In Your Brain! How To Switch Between Them

Episode Date: June 19, 2026

Dr Jill Bolte Taylor is a Harvard-trained neuroscientist and bestselling author known for her work on the brain, consciousness and recovery after stroke. In this moment, she explains the four “personalities” inside every brain, where trauma, addiction and emotional reactivity live, and how understanding your left and right hemispheres could help you feel calmer, more focused and more in control. Listen to the full episode here! Spotify: https://g2ul0.app.link/lV13mTW7w3b Apple: https://g2ul0.app.link/e/OK4itZY7w3b Watch the Episodes On YouTube: ⁠⁠https://www.youtube.com/c/%20TheDiaryOfACEO/videos Dr Jill Bolte Taylor: https://drjilltaylor.com/

I've just got back from Singapore and me and my team were there for a speaking engagement. Singapore has a different kind of energy to anywhere I've been. It's beautiful, it's clean, it's highly entrepreneurial and everybody is incredibly kind. And the heat and humidity really do hit you the second you walk out of the airport. We were having dinner one night with my head of my speaking team called Talia and she looks after our speaking in live division across the world. And she said that she'd been hosting her place on Airbnb while she was with me in Singapore, which I thought was incredibly clever because whenever you're away, your home sits empty.

when it could be easily part of someone else's travel experience. Airbnb sponsors our show, so I know about hosting, but hearing Talia speak about it made me realize just how straightforward it is. She just picks the dates that suit her, someone stays there, and by the time she's back from her trip, they've already gone. For me, it sounds like a very easy way to make a better use of your place and earn some extra money on the side. Your home might be worth more than you think.

And you can find out how much it's worth at Airbnb.ca.ca. So you said there's four personalities in everybody's brain. What are those four personalities? As we're looking at the brain, just from an anatomical perspective, the way evolution happens for the mammalian brain is that there are creatures who have a spinal cord, and there are creatures like that, like worms. And then a little brain, a little medulla will form at the top of that tissue. And then now that brain controls and streamlines information processing to the rest of the system.

And then we add a pawns. What's that? It's just a structure of cells. So this is the medulla. Yeah. We would have spinal cord there. And this is the ponds. Call that the ponds.

It's a group of cells. Yeah. It's a smaller brain. And in relationship to that ponds is this cerebellum. And the cerebellum has this gorgeous salin it called the Purgens. cell and they're like a hand. They're like, you know, two-dimensional. And they all line up like this. And then fibers run through those. And it's part of the mechanism of timing so that you have fluidity of movement because of the way those cells are aligned. So not all cells are created

equal and not all cells look alike. Cells have the right shape for the right job. So as then we we grow and now we have the mammalian brain. We're going to have the hippocampus, you've heard of that, for learning and memory, the amygdala, you've heard that for, am I safe. Am I safe? Are you safe? The amygdala, yeah, there's a group of cells right there that is scanning constantly. Am I safe?

Am I safe? And you're fine until you're not safe. Okay, so like threat detection. Yes, that's exactly what it is. You have two emotional systems, one in your left hemisphere and one in your right hemisphere. in the right hemisphere is going to be right here right now. Am I safe in the right here right now? So let's say all of a sudden a snake went by, and we would jump.

We would startle because it's your right amygdala saying, oh my gosh, am I safe? And then the left hemisphere is going, oh my gosh, it's a snake. No, I'm not safe. Push it away. And when we're calm, that's when the hippocampi, because we have two amygdala, one in each hemisphere, two hippocampi, one in each hemisphere. and when the amygdala are calm and you feel safe, now you can learn and focus,

focus with the anterior with the cingulate gyrus, and learn new things. So, you know, these groups of cells. Now, if you wipe out an amygdala, you're not going to feel any fear. You wipe out a language center, you're not going to have any language. You wipe out motor skills to your index finger,

and you can't, you're paralyzed. So every ability you have is because we have these brain cells that perform that function. So for the four parts of us, so we have an emotional system in each hemisphere. The emotional system of the right hemisphere, this is a right here, right now machine. Right here, right now. That's all it has. Doesn't have the past, doesn't have the future, doesn't know who you are.

Doesn't have anxiety, depression. Well, it has anxiety, but most of that is going to be based in the left hemisphere. Because this machine, the left hemisphere, has linearity across time. So this emotional system is remembering every traumatic event that ever happened to you that you don't want to have happen again. Is that where trauma lives in the brain? Trauma's living in there, as is addiction. Addiction, there's a group of cells in here called the insular cortex, and that's where craving is. And that's part of the limbic system of the left hemisphere.

And if you wipe out craving, do you still have an addiction? So this is, so let me just keep going. So we have these two emotional systems, and then we have these two thinking systems. And the thinking system is what distinguish us as humans from all of their mammals. Okay, so our mammals, our dogs love us. They're in any question about that. Our dogs can punish us when we're not very, you know, we don't show up and we've sent them to doggy care if they're not happy about that. So mammals have other forms, but we have this higher executive functioning.

And in the right hemisphere, it's right here right now. and in the left hemisphere, it's all about me. Because in there, in that thinking is my ego center in that prefrontal region, I, me, I exist. Back here, orientation association area, I begin and I end here. This is the package of me, the individual. I have a language. I can create language.

I can understand language. I can read. I can write. I have mathematics in there. And this motor system controls the opposite side of my body. So that's a personality. So what are the, to summarize them, what are the four types? Okay.

So when I look at a brain, and this is totally randomly named, and I did that because I had to communicate about it somewhere. So I call left thinking character one. And I actually give that part of my brain a name. I call her Helen. Hell on wheel, she gets it done. You're talking to Helen right now. She's giving you facts and detail.

She is all about what is right and wrong and good and bad. How do I fit myself into a society? How do I use my words in order to communicate? So this is the part of us that goes to work. It's our A-type personality. Character 1, left thinking. And that's on this side here. Yeah.

Well, it's all, it's this outer. This outer layer of cells is called the cerebral cortex. And the cerebral cortex is actually inhuman made up of mostly six layers of cells. It's very complex. In some areas, especially where you have sensory systems, it's just going to be. four layers, but this is a complex portion of the organ that separates us from other animals. What about Character 2? So Character 2 is going to be the left emotion. Now, the difference between the things you can say predictably about the left hemisphere is it has linearity across time

and it has me the individual. And my emotional system then has my past pain and it wants, And it's kind of always looking for a reason to knee-jerk react and have emotional reactivity. So so many people are trying to fix or heal or get rid of their emotional reactivity. This is a portion of our brain, which is running constantly in the background to protect us in the present moment when new information comes in. So we want to work with that and we want to appreciate it and we want to love on it and we want to be kind to it because it's generally not very happy because it is. storing all of our pain from the past. And what'd you call that? Character 2.

I call mine Abby. We could spend a whole semester talking about character 2, because character 2 is our pain from the past, and in our society, everything's about our pain from the past and our professional self. Character 3 is going to be the emotional content of the right hemisphere. Well, this is right here right now. What am I experiencing emotionally experiential? This is where, what's the temperature of the air?

What does it feel like to have clothing on? What does that feel like on your body? When you meditate, they ask you to become aware of your environment, right? And focus on your breath. Exactly. Because they want you to expand yourself one out of the thinking consciousness and right and wrong and good and bad structure, the box that we think in of the left thinking.

And they want you to stop, you know, thinking about your girlfriend. And, boy, we didn't really end it very well. Or, boy, I had a great morning this morning. Okay, so this is playful. So character three, it's young. We have two little people inside of ourselves, and that's the emotional. They're immature. We are feeling creatures as biological creatures. We are feeling creatures who think. So a lot of character threes, actually, we have character three moments that land us in jail. Because it's not thinking about consequences of behavior. It's just thinking, oh, yeah, the neighbor's pool. It's three o'clock in the morning. They won't notice. Let's go jump in their pool. And then the next thing we know, you know, we've been arrested. So then character four is the thinking portion of our brain. This is our wisdom. We go and we have experiences and we learn because neuroplasticity is real. And we have to have neuroplasticity.

And this is all about the cells. Neurons in real time reaching out, making new connections constantly, but their cell bodies are in position. But in order for me to make an association between you and something else, then I actually grow to you and I grow to the something else and then I learn about that. So our capacity to learn is the underlying feature is neuroplasticity. I would not be sitting here talking to you today if neuroplasticity didn't turn on fire when I needed it for eight years.

And it took eight years for me to use what I had in this brain to rebuild the skill sets of this brain. But the thinking portion, the character four portion of our brain, is the wisdom that we gain from the knowledge that we have had and we have associated it and we can relate to it. And this part, all it cares about is that emotion that I felt that morning, which was all, all that I'm allowed alive at all. And when we can connect to that, people, people, you know, it's a billion dollar industry of meditation to quiet what's going on in the left hemisphere so that we can open up the possibility to what's going on in the right hemisphere.

And it's our peace. We are wired at the core of our being of our right-thinking tissue to feel peace. And we do not exist in a world that is peaceful. So if we are functioning on an extreme left brain, left thinking, and we are emotionally volatile when people insult us, and we're all about the me, me, me, and we have forgotten about the we, look at the world we currently live in. And right now, we are so skewed to me, the individual, and I want more, and I'm against you because you're not a part of my tribe.

We balance that by knowing that I'm alive. It is this incredibly precious gift. The odds that I had to beat just to be here. Have you ever stopped to think about the odds you had to beat just to be here? Think about this. Now, first of all, think about this. The little egg cell, that would evolve into you eventually. It took form. It's about the size of, you know, it's an egg cell. It's tiny. But it took form during your mother's fifth week of gestation.

So your mother, your grandmother's pregnant, right? And that little egg cell that would be your mother has now made it into the womb. And during the fifth week of being there, the little egg cell that would grow into you took form. It differentiated into the ovum. And so you, the little egg cell, witnessed the next eight months of your mother's gestation, your mother's birth, your mother's screaming, your mother's toddler years, your mother's learning to sing and laugh and play and learn geography and mathematics all the way through her puberty. And then, so she's born with some 400,000 egg cells in her two ovaries.

And out of those 400,000 egg cells, approximately 500 of those egg cells are going to be the next follicular eruption, month by month by month with her period. And your little egg cell, imagine you're hanging out in your little ovarian follicle, and it's your turn and you're getting all prepped by the hormones of the body and you're going, oh my God, it's my ride, right? And you're this little egg cell. And then the hormones swoop by your little egg cell, and it beams you out. the fembriere of the fallopian tubes gather you up and you begin your promenade, your fallopian promenade on the way road to your mother's sacred womb. And in that moment, your father was there for you. And you were one of the lucky ones. And you beat the odds of all those egg cells. You beat the odds. And how can that not be something that we celebrate? The wonder of, the odds you had to be

just to be here. And then for the next nine months, that little egg cell is going to multiply its DNA, repackage that DNA. One cell becomes two, becomes four, becomes eight, becomes 16, becomes 50 trillion cells over the course of nine months. And you're multiplying egg cells at a rate of 250,000 new cells per second, per second, not per minute per second. You're this explosion, and literally the energy of the universe is what is fueling all of this from happening. You are nothing other than mass and energy working together. And then there's you. And it's like, how on earth can I have mental health problems and not acknowledge and have all for what we are? Oh my gosh. And that's what, that was the gift that stroke gave to my life. And you can see I get a little excited about it.

A little, yeah. We are so beautiful. We are so, beautiful. We are perfect and whole and beautiful just the way we are. And it's like if we would become balanced as a society, we would, I truly believe, truly believe with every essence of my being that our number one job is to love one another. When we love one another and we support one another and we encourage one another, we all grow and we will benefit as humanity. And when that happens, we will really recognize we have fragile resources on this planet and we need to nurture the planet as a part of us because we have a symbiotic relationship with this planet. Talks me up.

Why? Because it's, you know, lots of conversations about are we going to make it or are we not going to make it? What is the future of humanity? Where do we go? How do we, what happens? We live in a threat every day of our existence, of our, um, you know, existence being completely blown apart. Okay.

What are these? I would like for you to put those on. Okay. Now. Okay. And I just want you to sit in that for like, oh, just a, you know, 30 seconds, 20 seconds. Actually, it's pretty good look on you there. It's like men and black.

Yeah. Exactly. Okay. Now, I would like for you to pull your right one. The little, do you see how it's got a little edge? Yeah. You flip it up. It'll flip up.

Yeah. And flip it all the way up. Now, what you're doing right now is you are bringing light in from the lateral portion of your visual field. What does that mean? So close one eye and leave one eye open. Okay. That's a ball. Okay.

Down the middle is an artificial line. Yeah. Outside, the outside portion, that is called lateral. And the inside side is called medial. Okay. And so the lateral light is now coming in and that hits the medial side. of your retina. And the retina is the back of the eyeball. Okay, so the

light's coming in from the outside of my eye and it's hitting the inside of my eye. It's hitting the, it's coming out from the outside of your visual field, it's hitting the medial, internal side of your retina and then those fibers are boom crossing over to the

opposite hemisphere. Okay, I'll put a diagram on the screen for anyone. Yeah. Yeah. Yeah. So right now you are purposely stimulating your left hemisphere. So I'd want to just, how do you feel inside of your body? Just describe a few things to me. How do you feel?

Feeling analytical about anything, thinking about anything? My back has got a little bit of a pain in it. But otherwise, just very focused on doing this job as the host of the diary of a CEO. Beautiful, just focus, which is what that left hemisphere should do. So go ahead and flip that down. Okay. Yeah. And then just like stay for like 20 seconds and let everything kind of equilibrate to whatever

the darkness is that's in there. Yeah. All right. Okay. Go ahead then and pull up the other side. It's a good look. It's like a little flag right there. Yeah.

Okay. How do you feel? Weirdly, I felt more relaxed. Now? Or before? No, now I feel more relaxed. Your whole body just went calm. Yeah.

What else? Tell me something more. Any aches or pains in your body? I just feel way more relaxed. I feel like I'm laying low on a sun lounger. Yeah. That's what the right brain feels like. So you're bringing left information in from that, the light of the lateral side of your visual field.

It's hitting the medial portion of your retina and crossing into your right hemisphere. So what you're doing right now is you're sending light energy photons into the right hemisphere and it is pushing through. And now this is an. easy, easy way for people to control and choose how they want to be between their two hemispheres and really get to know, oh. How do I know this isn't just a placebo? Like, how do I, because I said I do feel way more relaxed.

I can't be bothered to carry on this in. But if you look at the anatomy, if you look at the anatomy, this is where light is coming in on the, you can't really see it on here, but that's going to be. information from your eyeballs, which would be sitting right here, right there. This is fibers. You're wired for this. This is how you are wired. That's why everything about you.

This isn't about a placebo having a behavioral impact. This is about the anatomy of the brain. Have they tested this in trials to see? Oh, absolutely. In fact, they just did a brand new one at Harvard and showed it on fMRI. Yeah. And have they done like a double blind control trial? they put these glasses on and then ask people how they feel?

Well, even more than that, they're doing, they're manipulating the light source in different kinds of ways. I'm not involved with that work, but I know that Marty Tyshire at Harvard as well as Frederick Schiffer. Now, Frederick Schiffer is a psychiatrist who has been doing psychiatry at Harvard Medical School for his whole career. And he would use these types of glasses with his psychiatric patients and would show the patient that there is a part of them that is less well and one side that is more ill. And so he would use the relationship between these two different characters, these two different personalities to find more peace and healing. I feel very, it's weird. I felt I just lifted up the right side again and put the left side down and I immediately felt, well, not immediately,

but it took a little while. It took 20 seconds. I felt focused again. Is that just placebo? No, that's what you're wide. That's why you can feel focused because of the cells that you are now stimulating. In the other hemisphere, it's not about focus.

It doesn't care about focus. It cares about the big picture and your relationship to the big picture. So it's not like the brain is just this soup of cells. These cells are very specifically organized every ability you have is because you have brain cells that perform that function. And all you're doing right now is preferentially stimulating certain cells. It's kind of like, okay, I'm going to open my eyes and I'm going to experience vision.

Well, that's not a placebo. If I want to be able to actively switch between these different parts, these four personalities in my brain so I can be most effective in a given situation. Is there a practice where I can control? my brain in that way. Absolutely. In your life, this is a practice. You don't just learn it and then go do it. This is a practice. You've got to say to yourself, first step. Step number one, recognize in this moment, am I using my left thinking judgment, listening to this conversation? And what is my judgment? Is my judgment, yes, this makes sense. This is interesting. I want more. Or is this, oh, this is just crap. I just can't go there. I got to turn it off. Or, okay, I'll give you an example.

once you know who your four characters are, once you have really thought about them, studied about them, paid attention to when they come out in you, what they feel like inside of your body, I can jump between all four in an instant. Because I know them so well. But is there a practice? You have to say, haven't you come in.

So this is what I do. Well, once you know the four of them, and the only way to know them is to practice with them, get to know them. When do you get really unhappy? Who unhappies you? When do you want to growl at people? I would name my name. And don't name a name, but you know, see, you went straight into that character too part of you.

That's the only part of you that holds grudges. Your right, thinking doesn't care about that. It doesn't even know about that because that's in the past. So here's the key. Step number one. Observe yourself. When am I being a character one? When am I at work? When am I speaking and organizing and making a to do list? And when do I like to be the boss? And when do I like to control? People places things in time and all of that. When am I doing that? Well, you know that part of yourself very well. He's probably called Stephen. The part of you that is not very happy. You know, your parents probably know this part of you. Your girlfriend definitely knows as part of you. Right? Yes. Okay. When are you playful? What does it feel like? It feels completely.

different than when you're at work or when you're not happy. When are you at play? And if you're not at play much, then you might want to give yourself a little bit more play. So I was working with a group of physicians because physicians are very busy people. And right now, the physician is a very high level of suicide. So I care passionately about this population because they're not finding any peace. Because society expects them to be a left thinking all the time. They're supposed to be the authority and they can't have any mental health issues because they're the ones we go to for mental health issues. So all they can do, they don't have time. They are busy, busy, busy, and they're not very happy about it.

And our system is a mess. So they're having to deal with that. So I was working with a group and I said, okay, I want you to take a chalk outside of the ER room and I want you to draw a hopscotch. And what happened was all these doctors in and out and these medical professionals, were hopscotching in and hopscatching out. And that, just that, help them bring their glee back just for a moment, just for an instant. So this is the glee and it's exciting and it's fun. And it's like figure out what brings you joy and do that. And no, and this is why it really helps to know this, because if you're going to say, okay, I'm going to go, I'm going to go play basketball. I come

from Indiana, everybody plays basketball. I'm going to go play basketball and I'm going to go do it for 20 minutes. And my character one is over here saying, we don't have time for you to go shoot some hoops, girl. We got business to take care of. We're on a deadline. And little character three comes in and says, I will refresh you. I will be your pause. I will refuel your spirit. I take the stress away from that subject, I release, I have all kinds of endorphins and excitement stuff going on, and then I go back and I do such a more creative and open job because I made space instead of just the drive, drive, drive, drive, do, do, do, linear, linear, linear. The beauty of being a human is you have all four parts of this brain. This is our design, but we are functioning with only one

online as conscious. Imagine, imagine. Imagine if you could say, in this, instant, I want to feel as though, just feel as though whatever your spiritual beliefs or your beliefs about a higher power, whatever, just call it the universe because we know there's a bunch of rocks spinning around in space and we're on one of them hanging on for life, just being human, right? So that's all happening. So, oh my gosh, I can say thank you to all those rocks for being in the positions they're in so that we're still here.

And I can feel this deep sense of gratitude. And as soon as I feel that gratitude and that, oh, my God, I exist at all and it could be over like that. And then it's over. But right now it's a party. Life can be play. What you just listened to was a most replayed moment from a previous episode. If you want to listen to that full episode, I've linked it down below. Check the description.

Thank you. I've just got back from Singapore. And me and my team were there for a speaking engagement. Singapore has a different kind of energy to anywhere I've been. It's beautiful, it's clean, it's highly entrepreneurial, and everybody is incredibly kind. And the heat and humidity really do hit you the second you walk out of the airport. We were having dinner one night with my head of my speaking team called Talia, and she looks after our speaking in live division across the world.

And she said that she'd been hosting her place on Airbnb while she was with me in Singapore, which I thought was incredibly clever, because whenever you're away, your home sits empty, when it could be easily part of someone else's travel experience. Airbnb sponsors our show, so I know about hosting, but hearing Talia speak about it made me realize just how straightforward it is. She just picks the dates that suit her, someone stays there, and by the time she's back from her trip, they've already gone. For me, it sounds like a very easy way to make a better use of your place and earn some extra money on the side. Your home might be worth more than you think, and you can find out how much it's worth at Airbnb.ca slash host.