Where Does Happiness Live in the Brain?

It’s been three decades since Anna Bryant Harris, then a young adult, was in the car crash that damaged her brainstem and right frontal lobe.

The brainstem helps regulate the vital functions of life, from breathing to consciousness and heart rate. The right frontal lobe is more mysterious, although neuropsychologists believe it is involved in higher-order thinking, such as executive functions and some aspects of personality.

Ask Harris about the crash and she’ll tell you the story she’s been told time and again. That’s because her own memory of the event was wiped out. But ask her how that car rollover many years ago has affected her life and she has no shortage of stories.

One of the surprises in Harris’ life after her traumatic brain injury (TBI) has been a challenging relationship with happiness. Though depression—that thief of contentment and personal peace—has always played some role in Harris’ life, she said it’s been much more challenging to find her way to happiness in the years since the accident.

“There are days in our lives when sometimes you wake up and your external life crashes down. For me, that can be overwhelming. Other times it’s my internal beasts that come alive and bring me down further. Sometimes both,” Harris said. “Sometimes I worry that it’s tied into my TBI.”

According to a theory developed by Eric Zillmer, PsyD, director of the Happiness Lab and the Carl R. Pacifico Professor of Neuropsychology at Drexel University in Philadelphia, Harris could be onto something.

“People right away think that happiness is only a way of feeling. However, it is much more. In fact, for Americans, it is a way of life. … We’ve been obsessed with being happy since the birth of our nation.”

“Surprisingly, there is no happiness center in the brain; there are, in fact, many different versions of happiness,” Dr. Zillmer said. “I have worked with many TBI survivors in the past, and of course, there are challenges. However, over time, perseverance and therapy can help survivors maximize their chances of recovery and, in turn, enhance their pursuit of happiness. But, ultimately, the brain’s complex relationship with happiness depends on the intact integrity of the organ.”

What Is Happiness?

Happiness can be so fleeting. Is it really happiness we’re talking about (along with Oprah, a seemingly endless supply of podcasts, and a huge wave of pop psychology books on the topic)? Or are people chasing something that’s more like contentment?

“In the past, I believe psychologists have looked at [happiness] too narrowly, mainly focusing on how happy emotions are processed. However, happiness can be as simple as sharing a meal with friends or as complex as discovering one’s life purpose. The brain processes happiness everywhere, and that’s pretty amazing.”

In the past, most neuroscience articles about happiness looked at brain mechanisms involved in modulating emotions, Dr. Zillmer said. “People right away think that happiness is only a way of feeling. However, it is much more. In fact, for Americans, it is a way of life; after all, the term ‘happiness’ was written into our Declaration of Independence. We have been told that we have the right to pursue happiness. We’ve been obsessed with being happy since the birth of our nation,” Dr. Zillmer said.

Although that’s quite a weight to put on a single word, Dr. Zillmer believes it’s beneficial because “it draws people’s attention and is part of a much larger investigation into positive psychology.”

Positive psychology is the scientific study of what is good about humans. Think of it as the flip side of clinical psychology—or the opposite of negative psychology, which looks to diagnose what’s wrong.

In his Drexel classroom, Dr. Zillmer prefers not to define the concept of happiness. “From a neuropsychological point of view, happiness is probably more of a philosophical term. In the past, I believe psychologists have looked at it too narrowly, mainly focusing on how happy emotions are processed. However, happiness can be as simple as sharing a meal with friends or as complex as discovering one’s life purpose. The brain processes happiness everywhere, and that’s pretty amazing. The brain is all in when it comes to happiness.”

But sometimes the brain appears to block certain types of happiness, like in Harris’ case. Why? Dr. Zillmer believes that the brain’s processing of happiness lines up in a one-to-one relationship with Maslow’s Hierarchy of Needs, a framework that organizes human motivations into five tiers.

Think about what you need to be happy on different levels: a roof over your head, water to drink and food to eat. When your basic needs aren’t met, there’s a good chance you’ll be unhappy. The brainstem also covers the basics (albeit some rather important basics) such as making sure your heart keeps pumping.

Next up on Maslow’s hierarchy? The safety and security necessary to protect your happiness, then human relationships and social systems, the creation of something meaningful in your life, and finally, contentment with who you are and what your role is in life.

“If you superimpose the anatomy of a brain onto a chart of Maslow’s hierarchy, it matches up, in my opinion,” Dr. Zillmer said. The parts of the brain that evolved first in evolution—including the brainstem and limbic system, which are involved in regulating emotions and motivation—sit at the lower end of the organ. The sections of the brain that handle thinking and self-control, especially the cortex and frontal cortex, came later in the brain’s evolution.

Dr. Zillmer’s ideas about this one-to-one comparison are backed by research in the World Happiness Report. The report focuses, for example, on safety and wealth, which are more traditional forms of happiness that are related to earlier derived brain functioning. However, the 2025 report also looked at the impact of generosity on people’s happiness, such as sharing a meal or being the recipient of caring behavior. In other words, higher-level happiness that depends on complex neuronal architecture.

If You’re Happy Do You Know It?

Sometimes. Other times it’s just that you’re not unhappy, “our default position,” Dr. Zillmer said. Happiness, contentment, joy, whatever you want to call it, disappears (and fast) when basic needs aren’t in reach. That’s the hardwired happiness that lines up with the brainstem. You might not really call it happiness just to be at a basic level of survival (breathing, not thirsty or hungry, housed) but if you don’t have those things “you would be very unhappy, right? Simple feels good,” Dr. Zillmer said.

“It’s a form of happiness that is pretty profound. If you don’t have it, you notice it,” he continued. “When humans start punishing people or incarcerating them, they’re taking all those things away. So that would be the brainstem and the ‘next step’ up, which we call the limbic system, a collection of brain structures that regulate your emotions, behavior, motivation and memory. Of course, it’s undoubtedly an important form of happiness.”

Dr. Zillmer theorizes that without this foundation of happiness (or the absence of unhappiness), the brain cannot fully process the next level of potential happiness. Not all pieces of happiness rely on each other, but the brainstem’s version is as essential for happiness as its other activities are for breathing, heartbeat and sleeping.

When Neurons Don’t Play Well with Others

In a perfect world where all brains are equal and behaving properly, an individual’s happiness level would probably be pretty easy to estimate based on how they were living and what they wanted out of life.

But, in reality, there are the wild cards: TBIs and neurons, which are the basic building block of the brain. Some neurons fire faster than others. Some are seriously slow.

“Neurons never, just never, sit there. But, one could say that half of all neurons are excitatory and half are inhibitory,” Dr. Zillmer said. “That’s important, because your brain is at war with itself between excitation and inhibition.”

The net result of that battle could be anxiety, which, like its counterpart, depression, undermines a person’s ability to be happy. Or, it could be happiness. “The wonderful thing about happiness is that if you are moving towards it, you are also moving away from despair and depression; you can’t be both at the same time,” Dr. Zillmer said.

But when people spend time together, as the World Happiness Report details, happiness can bloom. “Anxiety is contagious, but so is happiness,” Dr. Zillmer said. “Many forms of happiness are under our voluntary control and thus are within our grasp.”