The Happiness Lab with Dr. Laurie Santos - How to Break Up with Your Bad Habits

Episode Date: April 13, 2026

Breaking bad habits often feels like a test of willpower. We tell ourselves we’ll stop scrolling, eat better, or exercise more — and then fall right back into the same routines. So why is lasting change so hard? As part of our spring cleaning series, we’re revisiting a powerful episode from The Happiness Lab archives that reveals a surprising truth about behavior change: it’s not about willpower at all. Dr. Laurie Santos sits down with psychologist Wendy Wood to explore what the science of habits really says about why we get stuck — and how we can finally change. Along the way, we hear the remarkable story of American soldiers in Vietnam who abruptly overcame heroin addiction after returning home, offering a powerful clue about how habits really work. If you’re looking to break a bad habit or build a better one, this episode shows how small changes to your environment can make lasting change feel almost automatic. Experts Mentioned: Wendy Wood, Provost Professor of Psychology and Business, University of Southern California. Dr. Richard Ratner, Clinical Professor of Psychiatry and Behavioral Health, George Washington School of Medicine and Health Sciences Resources Mentioned: Good Habits, Bad Habits: The Science of Making Positive Changes That Stick, by Wendy Wood (2019) “How Do People Adhere to Goals When Willpower Is Low? The Profits (and Pitfalls) of Strong Habits,” by David T. Neal, Wendy Wood, and Aimee Drolet (Journal of Personality and Social Psychology, 2013) “The Pull of the Past: When Do Habits Persist Despite Conflict with Motives?,” by David T. Neal, Wendy Wood, Mengju Wu, and David Kurlander (Personality and Social Psychology Bulletin, 2011) “Ironic Processes of Mental Control,” by Daniel M. Wegner (Psychological Review, 1994) “How Permanent Was Vietnam Drug Addiction?,” by Lee N. Robins, Darlene H. Davis, and David N. Nurco (American Journal of Public Health, 1974) CBS News Lottery Draft 1969 (Archival Footage) "G.I. Heroin Addiction Epidemic in Vietnam" (The New York Times, 1971) G.I. Junkie (Documentary, 1971) Related Episodes: "A New Hope" "You Can Change" "Happiness Lessons of the Ancients: Sikhism and Daily Habits" See omnystudio.com/listener for privacy information.

Pushkin. Hey, Happiness Lab listeners, welcome back to our special series on spring cleaning your happiness. In honor of this season of new beginnings, we're clearing out all our outdated behaviors and mindsets so that we can refresh our emotional junk drawers, so to speak. We'll also be doing our own Happiness Lab closet refresh as we head back into the episode archives to find throwback insights from past episodes that you might have missed. And in today's episode from the archives, we're diving into a very tough spring cleanup job. We'll be exploring how to freshen up our habits. Now, I'm going to go out on a limb

and guess that there's at least one routine that you do on autopilot all the time, even though it makes you feel kind of crappy. Wouldn't you like to break free? To toss out that bad habit like an old pair of jeans and replace it with a routine that fits your current goals a bit better? That sounds awesome in theory, you're probably thinking, but is it really possible to break a well-learned bad habit?

Turns out, yes, totally possible. But the process is way easier if you have a more nuanced understanding of the way our brain's structure habits and how they really work. And that is what you're going to learn in our episode today. You're going to meet a scientist who sleeps in her running gear and a Vietnam war dock who turned to heroin addicts to debunk some important misconceptions about habit change. By the end of the show, you'll have gained some practical tips for dropping your own not-so-great routines and for building healthier ones. Sound good? We'll get ready to clear out all your bad habits with this week's spring cleaning

Happiness Lab throwback. Coming up right after this quick break. This is an I-Heart podcast. Guaranteed human. For starters, it was the last thing I particularly wanted to do. Like many young Americans back in 1970, Richard Ratner wasn't all that excited about going to war. I had just been married,

and when I found out that I was going to Vietnam, We try to figure out any way to get out of it, you know, which involved, oh, I don't know, talking to the military and seeing whether it was a sign that could be changed. None of it worked. They were well prepared for people who didn't want to go. The Army didn't want to hear Richard's excuses. As a newly qualified doctor, he had just the skills that the military desperately needed. Richard was one of many American men who were plucked from their civilian lives

and forced into the armed services. September 14,001. There was even a televised lottery draw, where young men were selected for military service and a stint in Vietnam based on their birth date. April 24 is 002. Richard was lucky enough to delay his service until after his medical training.

But arriving in Saigon as a 20-something new doctor was still a shock to the system. We are in buses where they have this steel mesh covering the window. and I'm absolutely sure that any minute someone is going to toss a bomb at us. But Richard wasn't a trained surgeon, heading to Vietnam to take care of bullet wounds. He was a psychiatrist, but he still wouldn't be treating depression or even PTSD. Richard was about to use his training to wage a war against bad habits, the kind of behaviors we really want to change, but somehow can't.

Richard would soon learn that our habits don't always work the way we think. His findings not only shocked scientists, but also change the way that researchers think about the science of behavior change, even decades later. And his story provides some important hints for how we can win our own personal battles with the bad habits that hurt our happiness. Our minds are constantly telling us what to do to be happy, but what if our minds are wrong?

What if our minds are lying to us, leading us away from what will really make us happy? The good news is that understanding the science of the mind can point us all back in the right direction. You're listening to the Happiness Lab with Dr. Laurie Santos. You've got to have those shoes shined. You've got to show up at formation. You know, you have to have your bed made. Richard's soldiers were trapped in Vietnam, far away from home.

Some were facing life-for-death situations on the battlefield. But according to Richard, the biggest enemy many soldiers faced was back in the barracks. It was boredom. Away from combat, soldiers spent their day doing repetitive tasks that they didn't enjoy. Shining boots, dealing with annoying superior officers, and generally just not having anything fun to do.

And that's why many of them wound up turning to a particularly bad habit, one that the Army really didn't approve of. People would just kind of get high. And, you know, not necessarily that different from if you come home from a hard day at the steel mill and, you know, go into the bar and have a few drinks. It's not totally unlike that. Yeah, but, you know, what was available wasn't a few drinks, at least for the soldiers who weren't 21. What was available was, like, incredibly hardcore heroin.

Exactly. The first phase was where soldiers were smoking marijuana. If you're smoking weed, it's not going to take too long for it to waft down to where the first sergeant's hooch was, and he'd come up looking for you. Conveniently enough, soldiers had access to a less smelly drug option. With the Golden Triangle, a massive area of poppy production just across the border, suppliers were ready and willing to sell an alternative drug to U.S. troops, heroin. They could do it under the nose of their commanding officers, and it was a great deal more potent. As one GI addict told the New York Times, the scagg was everywhere.

Estimates vary, but it's generally thought that around 20% of low-ranking soldiers used heroin. the Times called the addiction rates an epidemic. With hundreds of thousands of American troops stationed all over Vietnam, the government was worried that GIs would return to their families as desperate junkies. This notion that we had a whole army full of drug-crazed people who were going to be unleashed on these communities, truly had people frightened. The Army announced that anybody who was dependent on heroin could report to the amnesty center.

They would not be arrested or charged with criminal activities. They could come, they could detox, and then go home, you know, no harm, no foul. The American public demanded action. And so without a better plan, the Army opted to force the GIs to go cold turkey. When they came into the detox center,

we did not taper them off on heroin. I really had no idea. And I was sort of frantically trying to get information on how, does one properly detox somebody. But what Richard had even less of an idea about was how he was going to help soldiers stay clean once they got home. I mean, heroin isn't just any old bad habit.

It's an incredibly addictive substance. By making his soldiers go cold turkey, Richard could help his men get through the withdrawal phase, that first step to breaking the physical part of their addiction. But the bigger challenge was helping them avoid the behavioral parts of their addiction. That habit of turning to heroin, in order to feel better, whenever they were feeling depressed or bored or stressed, the almost automatic urge to reduce their craving with a quick hit.

Simply hoping that these men would have the willpower to avoid heroin wasn't going to be enough. Here we have these guys who were 18, 19, and when a little too much pressure is put on them, they pop. At the time, Richard was worried that there was no way to avert this wave of addiction. Sure the men could detox at his center. but no one seemed to know what to do to help them and overcome their awful habit, so that they could become healthier and happier. Now, I'm guessing most people listening to this podcast won't ever face a behavioral challenge

as hard as kicking heroin. But like those soldiers, all of us have bad habits that detract from our health and happiness. You don't need to be an opioid drug user to understand that it can be difficult to change our not-so-good ways. And the science suggests that the everyday habits that plague us can sometimes be just as hard to overreact, as the addictive kind. The problem is that the path to happiness requires changing a lot of these habitual bad behaviors. We need to stop griping.

We need to put down our phones, and we need to stop craving material possessions. But how do we do that? If you're like me, it probably feels like changing these repeated behaviors is really, really challenging. But what our lying minds don't realize is that we have a powerful mental tool

that really could help us achieve lasting behavioral change with you. ease. If only we understood how that tool worked. I wanted to learn more about why our intuitions about behavior change were so bad, and I knew just the person to ask. My name is Wendy Wood. I am professor of psychology and business here at the University of Southern California. Wendy is the author of a new book, Good Habits, Bad Habits, The Science of Making Positive Changes That Stick. Most of us are very good at understanding what we need. need to do better, to be healthier, to be more financially stable, to have happier families.

Most of us know what those things are. The problem, according to Wendy, is that most of us mistakenly think that changing our behavior requires willpower and hard work. I think that we admire willpower and we view it as a very positive attribute. The way that the Puritans thought they would go to heaven is through self-denial. and showing that they were strong enough to resist temptations. But there's a problem with this willpower is next to godliness notion, and that is that willpower doesn't really work.

When you exert willpower and control your behavior, what you're doing is you are thinking about the thing that you don't want to do. And in doing so, you give it energy to keep reemerging. So there's a sort of a self-defeating aspect to willpower that gets in our way. So if willpower doesn't work, what can we actually do to successfully tame our bad habits? The answer is that we need to be working smarter, not harder. When you observe people, when they are being effective at controlling their behavior and doing the right thing, say, eating healthfully or, saving money for the future. What they're doing is they're not exerting willpower. What people do is

they set up the situations around them to make it easy to repeat the desired behavior. And they repeat it over and over so that it becomes automatic. We don't realize how much of that we really could harness if we just knew how it worked. When we get back from the break, we'll do just that. We'll take a deep dive into how habits work and how you can harness them to behave in ways that promote your health and your happiness. The Happiness Lab will be right back. I get up in the morning.

I walk into my kitchen and making coffee is the first thing that comes to mind. Psychologist and behavior change expert, Wendy Wood, knows that engaging in routine is the secret to changing our bad behaviors. I don't ask myself how to do it. I don't need to do that. I've done it so often in the past. I don't ask myself whether I want coffee. Am I really tired this morning?

Do I need coffee? I don't ask those questions. I just do it. And then in the end, I get the reward of repeating what I've done in the past, which is that great cup of coffee. And that's how people who are really successful at meeting their goals, that's how they do it. Wendy's morning coffee making illustrates a willpower-free strategy that all of us can use to change our behavior for the better.

It's called habit formation. Habits are just the behaviors we repeat until they become sort of mental shortcuts. There are shortcuts about what you can do that's likely to get you the same reward as you got in the past. Habits can form for any repeated behavior that gets us a reward. Whether that reward is ultimately good for us, like a nice cup of coffee in the morning,

or bad for us, like a shot of heroin. But Wendy's work has shown that good habits and bad habits work exactly the same way. They have a very particular structure, one that involves three critical parts. The first critical part of habit formation is the reward. Rewards here are just behaviors that meet your goals, behaviors that make you feel good,

behaviors that achieve some outcome, that you're looking for. For Morning Wendy, that reward was having the positive taste of a nice cup of coffee. But habit formation can involve lots of other kinds of rewards, too. The endorphins that kick in after a good exercise session, the reduced boredom we feel after we do a quick social media check, or the satisfaction you get learning something new from your favorite podcast. Anything that feels nice or meets a goal can serve as a reward that leads to a new habit.

But habits not only require a reward at the year, end. They also have a second critical component, the routine. A routine is the specific sequence of actions that gets us to a reward. For Wendy's caffeine habit, that might be each step she takes to make her morning coffee. If you're a yoga lover like me, your routine might involve grabbing your mat and driving to your favorite studio. The science shows that having a specific routine is critical to habit formation, in part because our minds care about them a lot. In In fact, when your brain experiences something wonderful, it drops everything to remember the exact sequence of whatever you just did to get that reward.

And when it lays down a new memory of that sequence, it definitely doesn't want to screw anything up. And so it doesn't just remember what you did as a bunch of individual action steps. Instead, it stores your whole sequence of behaviors as a single solitary routine, what researchers call chunking. It even uses a totally different neural system to do so. When you're repeating a task that you have practiced many times in the past, you are relying on something called the sensory motor system, which involves the putamen, which is part of the basal ganglia. And when you start a new task in contrast, you're using much more of the frontal lobes because those are the active thinking parts of your brain.

And these two things are definitely connected, but they also function somewhat independently. And that's why habits are such fantastic mental shortcuts, because we don't need our conscious thinking frontal lobes to remember each individual action whenever we want our reward. The unconscious bits of our brain can just hit go and our minds get the entire perfectly stored routine for free. Driving is the prototypic habit, right? It's something we have to think about when we first learn to do it. But then over time, that thought becomes less and less necessary. And we start just responding automatically based on what we did in the past. And that achieves the goal of getting us somewhere we want to go.

And it does so efficiently and quickly, most of the time, unless you live in L.A. and then there's nothing efficient about driving. I want to focus in on this lack of awareness for a second because it's really weird when you think about it. I mean, our driving routine involves tracking lots of complicated stuff, from where your right foot is, to how fast your car is going, to whether there are pedestrians about to cross the street,

to where other cars are moving, to when a traffic light might change, to when you need to click your turn signal, and to whether you have your radio set to your favorite podcast. It's amazing that we can juggle all that information at all. let alone that we can do so easily and unconsciously. But that is the amazing psychological power of habits. Once we form a new habit,

we get to engage in all kinds of complicated behaviors without a moment's thought. And that's why habits are so much more effective than willpower for changing our behaviors. Once we make the things we want to do habitual, they don't require any more work. The problem, though, is that not all of our unconscious habitual behaviors are good for us. So sitting on the couch when you get home at night and eating potato chips, that's just as much of a habit as going home and then just heading out to the gym. One looks habitual and structured to us, and the other might look sort of a bit lazier, but they're both habits in the same way. Sadly, those lazier not so good for us routines are just as automatic as our positive habits, which means that our bad habits.

which means that our bad habits, the ones that inhibit our happiness, are really, really hard to shed. We might want to shut those habits off, but we can't because our minds are on autopilot. But Wendy's work shows that we do have some control over when our habit routines get turned on, whether our minds unconsciously decide to execute that sit on the couch and munch behavior or the throw-on-our-in-clothes one. The answer comes from the third critical part of our habit loops, the context. The context is any part of our situation or environment that cues our behavior.

For Wendy's coffee habit, the context was a location, being in her kitchen, and a time of day, it was morning, and a preceding event. She had just woken up. For Richard's heroin addicts, the context might be their barracks, or the site of other GIs using drugs, or just being in Vietnam. In our research, we found that context can be pretty much everything around you that's not. you. It can be the people that you're with. There are certain people who trigger certain behaviors that we've done with them in the past. You may have friends that you typically go and have a drink with. And if you see them again, that's what tends to come to mind. The moods we're in can also be triggers. So I think that one of the most common triggers,

for checking your cell phone is being bored, even if you're in a meeting and it's quite rude. You may find yourself checking your phone. You don't want to be rude, but the idea of your phone just comes to mind when you're bored. When our brains notice a context that's associated with a habit, one that goes with a particular routine and a certain kind of reward, we get an incredibly strong urge to execute the habitual behavior. Even if it's a behavior that's no longer useful or relevant, In fact, Wendy's work has shown that cues can elicit habitual behavior, even when the rewards from those behaviors aren't even there anymore. She tested this out in a clever study involving movie trailer screenings.

One group of subjects watched the movie trailers on a computer in Wendy's lab, just like a typical study. But a second group of subjects got to watch the trailers inside a movie theater. Wendy was interested in whether the movie theater cues spurred on a habitual movie-going behavior. popcorn eating. But she also wanted to know whether her subjects would engage in that habitual behavior,

even when it was no longer rewarded. To do that, she varied the deliciousness of the popcorn she offered. Some people got popcorn that was stale, and it was really stale. So it had been sitting in our lab for a week in a plastic bag.

It was pretty gross. Others got popcorn that was fresh that had just been pommed. Very few people who watch the film in the lab ate the gross popcorn. They didn't have any cues that pushed them to engage in an otherwise yucky behavior. But what happened to the subjects who experienced all the normal cues of being inside a cinema? Well, it depended on how they normally acted when watching movies. People who had habits to eat popcorn in the movie cinema ate just about the same

amount of stale popcorn as fresh. They could tell us when we asked them that they hate the stale popcorn, they ate it anyway. People who didn't have habits, deep popcorn in the movie cinema, they did just what you'd expect. But rationally, we think we would all do, which is eat the fresh popcorn, but if they got a bag of stale, just leave it. When our brains see a cue that's been associated with a habitual behavior, we can't help but execute that behavior, even when the behavior is no longer rewarding. But despite the power of these cues, Wendy has found that we don't often realize

how much context affects our behavior. And that means we often forget that we can't count on our habitual routines once the cues go away. And Wendy has seen the negative effects of removing our habitual cues firsthand. I bought a new car a few years ago that has all kinds of wonderful safety sensors

so it beeps when I get close to an obstacle. And I hated that at first. It really irritated me because I wasn't used to it. But I started responding to those signals automatically. Over time, you just stop noticing them. When the car beeps, you just automatically respond to it. And I didn't realize how automatic that had become, how much of my driving habit that had become,

until I rented a car and it didn't have that warning sensor system. And the first thing I did is I backed into a brick wall. The Happiness Lab will be right back. I am a Vietnam veteran, a ex-marine medic, and an ex-morphine addict. Back in 1971, a documentary called GI Junkie followed a group of returning soldiers going through rehab. I don't need no pills no more. We're a needle in my arm. I mean, if I'm there, I know what I want, I'm going to go get it.

The film argued that nearly 40,000 hardened GI junkies were about to return to American soil and would soon become a major problem. But in reality, no such army of drug addicts actually existed. The kind of surprising key is that I think once these soldiers got on the plane and got back home, you know, they were good. Their cravings didn't kick in. They weren't trying to find the stuff once they got back. Exactly. That's exactly right. And no one, I don't think anyone could have predicted that.

Psychiatrist Richard Ratner had been sent to via a doctor. to diffuse what one newspaper called a time bomb. And that's what made Richard's soldiers' outcomes all the more surprising. A team of researchers followed addicted Vietnam vets after they came home. The scientists interviewed the men about their recent opioid habits and even conducted drug tests using urine samples. And what they found pretty much stunned everyone, including Richard. Only a very tiny percentage of soldiers continued their drug use after they got home.

more than 90% of soldiers stayed clean. Compared to the typical heroin user, Vietnam vets seemed to have little trouble kicking the habit. The study was so shocking that at first researchers didn't even believe it. But slowly, behavioral scientists like Richard were able to figure out the soldier's secret. They were able to use their contextual cues to break their bad habit. Probably the majority of users would basically kind of detox on their own. and they would self-detox.

While they used this crutch to help them get through military life over there, they understood that the home environment is very different from this environment. Richard realized that a few hours on an airline and had changed back into civi clothes was enough to break his soldier's habit routine. They weren't bored or stressed anymore, and they weren't hanging out with their drug-taking buddies. They also didn't have easy access to cheap heroin. Nearly every single one of their habit cues was different.

Most of these guys, they got home and they kind of reintegrated into their previous lives. Richard's veteran's success in kicking heroin has now become a classic example in the science of behavior change. Because of a simple context switch can be powerful enough to help someone overcome heroin addiction. Imagine how powerful it can be for changing simpler behaviors, like the ones many of us want to change. We did some research where we beeped people once an hour to figure out what they were thinking, feeling, doing. And what we found is that about 43% of the time people are doing what they did yesterday and the day before in the same context, and they're doing it without thinking much about it. The idea that nearly half of our waking day is on autopilot, that we're constantly governed by cues in context. is pretty shocking.

But if that's true, then it gives us a powerful opportunity to change some of our daily behaviors. If we can use our conscious minds to exert some control over the context we find ourselves in, then we can shift our bad behaviors to the ones we want to adopt. Our environments can do the same thing for us in pushing us to help us meet our goals and making it hard for us to stray from the good behavior.

that we're trying to practice. This is something you can do right now, whether in your home or at your workplace. Think of it as feng shui for habits, but with an actual scientific basis. Make small changes in your environment that provide the cues you need to promote good behaviors. Wendy's research has shown that simple changes like these work time and again. In one steady, people had a bowl of apple slices and a bowl of hot buttered popcorn, When the apple slices were right in front of them and the popcorn was arms reach, people ate a third less calories than when the popcorn was right in front of them and the apple slices were a reach. I mean, we're talking a minimal distance that makes little sense to our conscious thinking cells, but to our habits and our automatic reacting cells,

That's a big difference. We don't realize how much of a difference proximity makes to our behavior. But context doesn't just affect what we reach for when we're hungry. There are lots of simple ways we can use the cues around us to disrupt the autopilot behaviors we don't want to engage in. There are forces in our environments that make some actions more difficult and other actions easier. And those resisting forces can be termed friction. It just becomes too difficult. The same sort of friction helped Vietnam vets avoid drug use when they returned home. Many had never taken heroin before going to war, so they'd actually have to find a dealer. And the heroin available in the States was a far lower quality, which meant that soldiers would have to inject it rather than snort or smoke it. The price was also far, far higher.

And the GI's mood had shifted completely. Those feelings of boredom that drove them to use opioids, those were replaced by the excitement of being home and just the pace of normal life. each and every one of the cues that prompted that heroin routine was gone. And this is super important because these contextual changes were more powerful than any of the detox ideas the Army came up with. The new cues meant that soldiers just didn't think about the reward of a quick heroin hit because their entire habit chains were disrupted.

But frictions can also be introduced to tackle the problems associated with legal drugs. In the middle of the last century, we all learned that, smoking was bad for us. About half of America smoked at that point. But smoking still didn't go down. Smoking rates continued reasonably high until the U.S. decided to put friction on smoking by taxing cigarettes so you can't afford them as easily, banning smoking in public places, and by making it difficult to purchase cigarettes so that you actually have to ask somebody. All of those things combined put enough friction on smoking so that the smoking rates in the U.S. are now down to a level of only 15% of us smoke. And that's because of friction.

Even if you don't smoke or use illegal drugs, there's a lesson here for you. Think about the things you want to change in your life, the bad habits you want to stop, or the good habits you want to adopt. We can use the conscious part of our brain to increase friction to inhibit our bad habits. and break down the barriers that prevent us from doing the good ones. Are there social media apps that drive you nuts, but you can't help checking whenever you pick up your phone? Well, delete them. Do you want to call your mom more often?

Well, then choose a photo of her as your screensaver. Don't want to buy certain items in the store? Plan your shopping trip to avoid the candy aisle. Or maybe you want to try some of the new habits that we've talked about in this season, like experiencing more gratitude. Then download a gratitude app, and stick it front and center on your phone.

Or maybe you want to make better use of your time, then put that time windfall list, somewhere you can see it easily. In all of these examples, you can hack the cues around you to help promote the kinds of behaviors that you want in your life. Wendy had to go through this exact same conscious process

when her daily fitness habit took a nosedive, thanks to motherhood. Rather than powering through or giving up, she analyzed where her growing family was adding a bit of friction to her work, out plans. Every time I decided 2 o'clock, 3 o'clock, 4 o'clock, maybe 6 o'clock tonight I'll exercise. Something always comes up when you have little children. So I decided I would have to start exercising early in the morning, although it was a really dreadful thing to start doing. Once you get

used to it, it actually is very efficient. So at 6 a.m., Wendy would be ready to exercise. But what exercise? Wendy realized it had to be something with as few frictions as possible. I didn't have much time to drive to a gym or do any fancy workout thing. I couldn't go to a class. I just didn't have that level of control over my time. So it had to be something that was very efficient and easy for me to do. And putting your running shoes on and going out the door is probably the most frictionless kind of exercise that you could imagine. I actually used to sleep in my running clothes.

I hate to admit this, but that was another thing that reduced the friction. Talking with Wendy has really inspired me to think about how I can use my conscious brain to hack the autopilot of all my bad habits. I'm already planning strategies I can use to increase or reduce friction, so I'll be able to reach my own well-being goals, literally without thinking. I hope you've gotten some insight into how you can hack your own habits, And I hope you'll be willing to form a new happier habit and set up all your context cues to remind you to come back

for the next episode of The Happiness Lab with me, Dr. Laurie Santos. This is an I-Heart podcast, guaranteed human.