That Neuroscience Guy - The Neuroscience of Irrational Thinking

Episode Date: October 23, 2024

In today's episode of That Neuroscience Guy, we discuss the neuroscience behind why we make irrational decisions. 

Hi, my name is Olof Krogolsen, and I'm a neuroscientist at the University of Victoria. In my spare time, I'm that neuroscience guy. Welcome to the podcast. Okay, I have to admit, like everyone, there's times where I've acted completely and totally irrational. I have not acted in a way that is logical or that Spock would approve of. So on today's podcast, why we act irrationally. So basically, we could define operationally that an irrational action is something that we do that isn't rational.

It's a choice that seems a bit out there, and it doesn't make a lot of sense. All right. So why do we do this? Well, if we think about decision making, we've talked about it a lot. So let's just do the quick review. The simplest model of decision making is that you have values for choices. There's a value for choice A and there's a value for choice B, right? And if the value for choice A is higher than the value for choice B,

then we choose choice A and vice versa. So let's just consider a model where the rational choice is choice A and the irrational choice is choice B. And there is a value for each of these choices. Now, presumably, most of the time, the reason that we choose choice A is because our logical brain is kicking in and we basically choose that choice, all right? But every once in a while, we choose the irrational choice. Now, we make these irrational choices.

Why is it? Well, an easy thing to look at is emotion. Again, emotion. I feel like I say it way too much. But as I said on the last episode, we can focus on the emotional part of the brain and our emotional system. So not just the amygdala. I had to say it. Well, our emotional system bias our choices.

We know that. All right. So the reason we might act irrationally is because our emotional system is biasing the value of the irrational choice so that it's higher than the value of the rational choice. Now, how do we tame our emotional system? Well, we step away. We know that the responses of the emotional system are quick. They ramp up quickly, but they die down quickly. So sometimes if you can, to avoid irrational choices, you simply need to calm

down, right? You need to take a breath, count to 10, go for a walk, have a cold shower, and hopefully the value of the irrational choice will calm down. So that's the simplest reason why we do it is something has valued the choice of the irrational outcome or the value of the rational choice higher, and then we choose it. Now, this could also come down to the way we view the world as well. We talked about this again in the last episode, but we have a worldview. Left prefrontal cortex is maintaining it, but maybe the right prefrontal cortex has changed our worldview such that the irrational choices now seem like normal choices.

All right. And I'll give you an example of this I've used before quite a long time ago. But if you look at serial killers, for most serial killers, the choices they make are rational within their framework. So for us, they would be irrational choices. But in their worldview, the choices they make make sense to them. They're rational to their system. So what we call an irrational choice is actually a rational choice for them. It fits their worldview. So our worldviews could change for any number of reasons, like something traumatic, for instance. If you go through a painful divorce, it might disrupt your worldview.

It might change your worldview. And all of a sudden, the choices you wouldn't normally do seem rational to you, but they're irrational to others. So you have to think about this when you think about irrational decisions. There are irrational decisions that we make, and there are decisions that we make that are rational for us, but are irrational for others. And this is, of course, is disruption within the prefrontal cortex. And as I've already mentioned, it's the emotional system, you know, valuing these choices. Now, there are a lot of other factors that can cause us to make irrational decisions. Let's take a simple one like alcohol. Well, guess what? What is alcohol doing? We've

talked about this on the episode on alcohol, but alcohol effectively suppresses the activity of the prefrontal cortex, at least relative to a greater extent than other parts of the brain. So once you've consumed alcohol, choices that you wouldn't normally make, like driving while you're impaired, if you're completely sober, is something we go, well, that's a really dumb idea. But once you've had too many drinks, your value system is skewed because of the alcohol. And these could be other drugs or other things that bias your system. And all of a sudden, the irrational choice, that is to drive impaired, seems like an okay choice to make.

So external factors are a big one here. And I'll throw out a bunch of them. Sleep. People that don't get sufficient sleep, that are what we call sleep deprived, all right, they make more irrational choices. And again, it's because their entire decision-making system is skewed. If you're extremely fatigued, all right, because of lack of sleep, your brain might be more emotional or it might just be looking at the world differently. But again, that can skew your decision choices. So lack of sleep can bias you and make you make irrational choices. That's why if you

are struggling with a lack of sleep, all right, you shouldn't, you know, you shouldn't be making big decisions. That's like this idea of flying in on the red eye flight for an important business meeting is actually crazy. From a neuroscience perspective, you should fly in a day or two early, rest, get your body clock sorted, make sure you're exercising, all those things we talk about with good brain health, and then make decisions. So we've talked about lack of sleep. We have talked about alcohol. Well, what else is there that can bias our decision systems? Well, there's stress and anxiety.

When the body is stressed and we're experiencing stress and or anxiety, we're in a different mental state. And as a result, that can bias our decision-making choices, right? It skews those values. Now, how it skews them depends on the situation and the context, but presumably if you make the irrational choice, it's because of stress and anxiety, right? And we talked about cortisol release, and I'm not going to revisit all the episodes of the podcast that are pertinent here, but the key point is, is that if you've got a bunch of hormones and neurotransmitters running around doing a bunch of things, that can bias your decision system.

And when it's biased, that might lead to something that appears to be an irrational choice. Pressure. Another factor. It's similar to stress and anxiety, but there are people that experience pressure or they don't have stress and anxiety. So I'll deal with pressure separately. But the bottom line is, if you're under pressure, whether it's from work or a significant other, like someone's leaning on you, that might cause you to make an irrational decision. And the example I want to use here is pressure in the sense of a time crunch. If you think back to the way that we talked about decision-making over time back in the episodes on decision-making,

the values for our choices, the value for choice A, the value for choice B, they're not constant over time, or at least they usually aren't constant over time. These values change over time as we accumulate evidence and we learn new things, or just due to our body state. Now, what happens with this is to get the appropriate value assessment might take a certain amount of time. Let's call it two weeks. But if your boss tells you you have to make a decision in the next three days, that pressure means that you might choose the wrong choice through an inaccurate value assessment. So you haven't had the time to sufficiently develop a proper value assessment, and that's why you make the irrational choice. And that's all there is to it. Our rational brain can normally sort this out. All right.

But our value system might be skewed for some reason, traumatic event. All right. Emotions might be biasing us, which is also tied to that. And then there's these external factors such as, you know, alcohol and drugs, sleep, stress and anxiety or pressure. you know, alcohol and drugs, sleep, stress and anxiety or pressure. And it's simply put, all it's doing is making the irrational choice seem rational to our brain or seen acceptable. It wins the higher value argument and that's the choice you end up making. Okay. As ever, I hope you found that interesting, a little bit on rational choices and why we make them.

Don't forget, there's the website, thatneuroscienceguy.com, links to Etsy, Patreon. Of course, there's threads and X at thatneuroscienceguy. Please send us ideas. We really want to know what you want to know about the neuroscience of everyday life. I'll just point out we've stopped doing neuroscience bites so we're generally looking for ideas that you know I can make 10 or 15 minutes out of as opposed to answering single questions one thing Matt and I have discussed is bringing back not bites but a couple of Q&A episodes where we fly through the quick answer questions so we'll be doing one of those in the near future because we've got about 10 questions that basically I can answer in about 90 seconds. So we're going to go that route. And of course, there's the podcast itself. If you haven't yet, please subscribe and thank you so much for listening. My name is

Olav Kregolsen and I'm that neuroscience guy. I'll see you soon for another full episode of the podcast.