PDF Summary:The Molecule of More, by Daniel Z. Lieberman and Michael E. Long

Could a single molecule drive all of your ambitions, decide when you fall in love, and influence how you think? According to The Molecule of More, the answer is yes; a chemical called dopamine does all of that and much more. In this book, psychiatrist Daniel Z. Lieberman and educator Michael E. Long explain the many ways that dopamine affects your behavior, your emotions, and even your beliefs.

In this guide, we’ll explain what dopamine is and how it affects us. We’ll also discuss how some other chemicals in your brain work with—and against—dopamine, and why finding the right balance in your brain chemistry is the key to happiness.

Our commentary adds background information about the biology and chemistry of your brain. We also clarify how dopamine interacts with other chemicals, and even the structure of your brain itself, to produce the behaviors that the authors discuss.

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Dopamine, Creativity, and Mental Health

Although dopamine has the positive effect of driving creativity, Lieberman and Long say that it’s possible to have too much dopamine—to be too creative and start making connections between ideas that really are unrelated. This is a common feature of mental illnesses like schizophrenia and paranoia, where someone might imagine some massive conspiracy because they’re inventing connections between unconnected events.

(Shortform note: Some psychologists believe that conspiracy theories aren’t just random products of a brain with too much creativity and dopamine, but that they serve as a self-soothing anxiety response. If there’s a group secretly orchestrating events (for instance, the Illuminati are popular scapegoats), that means nothing is ever truly random; therefore, any future disaster can be predicted and prepared for. While belief in a global, nearly omnipotent group like the Illuminati might seem terrifying, some people find comfort in having a tangible enemy to fight instead of thinking they’re at the mercy of chance.)

This happens because dopamine is responsible for what psychologists call salience, which means how relevant something seems to you, personally. When your dopamine activity is too high, things can feel relevant to you when they actually aren’t. This could be as mundane as assuming that a coworker’s bad mood is a result of something you did, or as unusual as believing that a popular song is secretly about you.

Dopamine’s Effects on Salience and Psychosis

While some experts agree that dopamine is connected to mental illnesses such as schizophrenia, they add that not everyone with high dopamine levels develops psychotic symptoms, and treating patients for high dopamine levels doesn’t cure all the symptoms of schizophrenia. These researchers believe that elevated dopamine in specific areas of the brain causes those psychotic symptoms, that imbalances of other neurotransmitters must be involved, or both.

Some studies have found that aberrant salience (thinking things are relevant when they aren’t) can be the result of heightened dopamine levels, and it’s an early indicator of psychosis. Mental health professionals can use evidence of aberrant salience to diagnose mental illnesses like schizophrenia before more serious symptoms emerge. However, this connection only applies in severe cases, such as the person who believes that popular songs are really about them. The other example from above—thinking people are upset with you when they really aren’t—is common and usually isn’t a sign of mental illness.

How Dopamine Affects Desires and Decisions

While dopamine is a powerful and versatile chemical, Lieberman and Long say it has two additional shortcomings.

First, dopamine doesn’t help you judge whether you should want something—in other words, whether it’s actually good for you. For example, looking at social media produces a steady stream of dopamine, but there are probably better uses of your time than scrolling through your feed for hours.

Second, dopamine makes you want things, but it doesn’t help you enjoy those things once you have them. The authors say that’s why people tend to want whatever they don’t have—they constantly strive for greater achievements, more recognition, more wealth, more possessions, and so on.

For instance, someone who has a big collection of video games might impulsively buy the hottest new release and enjoy a quick hit of dopamine, only to leave that game collecting dust on a shelf next to everything else they haven’t played.

Breaking the Cycle of Dopamine Urges

These dopamine-driven impulses can lead to a pattern of behavior that’s commonly referred to as the hedonic treadmill. This is an endless cycle of chasing something we think will make us happy, experiencing a brief moment of pleasure from attaining it, then chasing the next thing once the pleasure wears off. Psychologists call it a treadmill because we’re constantly “running” after happiness, but we keep winding up in the same place emotionally.

There are several ways you can get off the treadmill:

Ask, “Do I need this?” When you want to buy something for yourself, take a step back and ask if it’s something you need or just something you want. Another way to approach this is to ask, “Will this be good for me?” If so, it may be something you need; if not, it’s only something you want. (However, when answering this question, remember that recreational activities like reading, traveling, and creative hobbies are important to your health—so don’t dismiss something as a want just because it’s not directly helping you toward a fitness or career goal.)

Practice gratitude. Instead of thinking about what you don’t have yet, remember and appreciate what you do have. Examples might include your health, family and friends, job, home, and accomplishments.

Find pleasure in simple things. You can find contentment and tranquility without having to spend money or a great deal of effort. Instead of chasing after big, showy possessions and accomplishments, remember the pleasure of simply taking a walk or watching your favorite TV show.

How Dopamine Balances Itself

Lieberman and Long also say that, fortunately, your brain has a system to suppress and control those dopamine-driven impulses—and it does so by using more dopamine.

This regulatory system is found in the frontal lobe (the part of your brain that handles reasoning and long-term planning). While the dopamine produced there still creates feelings of motivation, in this case, the dopamine motivates you to think things through and figure out the best way to get what you want.

For example, suppose you’re feeling hungry; dopamine will motivate you to find something to eat. However, the dopamine in your frontal lobe will also motivate you to decide what to eat, how best to get it, prepare it, and so on. This also lets you do things like balancing your urge to eat junk food with your desire to reach long-term health goals. Without that regulatory system, you’d just take whatever food is most convenient and immediately eat it, regardless of the impact on your health.

How Brain Structure Contributes to Impulsive Behavior

If we have this regulatory system in place, why do we still act impulsively? One reason is because of how our brains are structured; reasoning is one of the slowest and weakest brain functions we have, while dopamine-fueled desires can affect us much more quickly and strongly.

In Behave, Sapolsky explains that the human brain has three different “levels”: core functions (base level), emotions (middle level), and reasoning (top level). Furthermore, lower levels can bypass and override the levels above them.

That’s why, when you’re feeling a strong emotion, it’s unlikely that you’ll be able to reason your way out of feeling it—in fact, you might find it hard to use reasoning at all. If the emotion is strong enough, you might impulsively act on it before you even have the chance to consciously think things through; it bypasses your top-level brain functions completely.

For example, if you’re extremely hungry, your desire for food might be so strong that it overrides any sense of logic or thoughts about your long-term health goals. As a result, you might impulsively buy fast food or eat whatever junk food is nearby. By contrast, if you’re only slightly hungry, you’re still able to use your reasoning to make wiser health choices—and dopamine in your frontal lobe can assist with this, as Lieberman and Long describe.

How Dopamine Has Defined Human History

Lieberman and Long have explained numerous ways that dopamine affects our individual thoughts and behaviors, but just how big of an impact does it really have? According to the authors, dopamine is the reason humans are the dominant species on Earth.

(Shortform note: Dopamine is a major factor in human dominance, but it may not be the whole story, especially since all animals have some level of dopamine. Instead, some experts believe that humanity rules the world because of how well we work together; people can cooperate in large groups and can flexibly reassign roles within those groups as needed. Dopamine drives those behaviors of cooperation and adaptability, but they’re only possible in the first place because of our highly developed brains. Some other animals can form social groups that rival ours in size (like ant colonies) or in flexibility (such as wolf packs), but no matter how much dopamine they produce, no other species can match us in both areas.)

To support this claim, Lieberman and Long trace the history of one particular gene variant (called DRD4-7R), which makes people who carry it even more responsive to dopamine than usual. In other words, many of the dopamine effects we’ve discussed—motivation, creativity, and interest in learning new things, to name a few—are stronger in people who have the DRD4-7R gene.

The human race originated in Africa about 200,000 years ago. Researchers have traced major human migrations since then, up until the present day when we’ve become the dominant species across the planet. When scientists compared those migration patterns to the prevalence of DRD4-7R, they found that the farther a group of people traveled from their African origins, the more common that gene is among them. According to Lieberman and Long, this suggests that heightened dopamine effects are what drove people to explore and settle new territories until humans effectively ruled the Earth.

(Shortform note: There’s a strong correlation between the frequency of DRD4-7R and how far a group traveled from Africa, but that doesn’t necessarily mean that gene caused those migrations. This is because correlation is not causation—there could be some unknown factor influencing both things, or it’s possible (though unlikely) that the correlation is just a coincidence. The only way to truly determine whether one thing causes another is by experimenting, which isn’t an option when discussing ancient humans.)

Dopamine’s Counterparts: The ‘What Is’ Chemicals

As we’ve discussed, dopamine is the “what if” chemical because it helps you look to the future. Lieberman and Long also say there are a number of different chemicals responsible for helping you experience and enjoy the present. We’ll refer to them as the “what is” chemicals to provide a clear counterpoint to dopamine, the “what if” chemical. For example, one notable “what is” chemical is serotonin, which produces feelings of contentment and well-being (not to be confused with the dopamine-driven feelings of pleasure and excitement).

These “what is” chemicals are relevant to the discussion of dopamine because they often compete with it. It’s impossible to completely focus on the present and the future simultaneously because your brain can’t process all those chemicals at the same time.

(Shortform note: While Lieberman and Long say that the “what is” chemicals work against dopamine, neurologist Robert Sapolsky says in Behave that dopamine and serotonin work together to motivate us. However, Behave also explains why different experts may make different claims about the relationship between dopamine and “what is” chemicals: The human brain is extremely complex, so the effects of any particular chemical often depend on countless other factors—not even neurologists fully understand how all of the neurotransmitters interact. In other words, it’s not totally accurate to say that dopamine is the “motivation chemical” or that serotonin is the “happiness chemical”; those are just simplified explanations that make brain functions easier to understand.)

Happiness Requires Both ‘What If’ and ‘What Is’ Chemicals

Since “what if” and “what is” work against each other, which should you focus on producing? Both, according to the authors.

Lieberman and Long say that healthy, sustainable happiness involves finding the right balance of dopamine and the “what is” chemicals; you’re happiest when you’re content with the present and excited about the future. Since it’s impossible to totally focus on the present and the future at the same time, this means shifting frequently between “what is” and “what if”—for example, you might work on a task that keeps you fully engaged, then when you’re done you feel excited about having gotten closer to one of your goals.

(Shortform note: Lieberman and Long’s advice to balance “what if” with “what is” goes against the advice of many self-help experts, who say that the key to happiness is to always live in the moment. For example, in Maybe You Should Talk to Someone, psychotherapist Lori Gottlieb says she got over a crippling midlife crisis by learning to enjoy each moment as it comes (instead of obsessing over the past or worrying about the future). However, as we’ll discuss in the next section, people respond more strongly to dopamine than to the “what is” chemicals; therefore, it’s likely that placing such extreme emphasis on the present actually creates the balance that Lieberman and Long discuss.)

How can you achieve this balance? The authors suggest finding a career or hobby that requires you to concentrate on what you’re doing at the moment, but also to plan ahead and make progress toward longer-term goals. For example, practicing martial arts demands your full attention in the present, but it also involves striving for higher ranks and training for upcoming matches. Any type of creative work has a similar effect: You have to focus on the work you’re currently doing, but you also need to have an idea of what the finished product will look like, whether it’s a painting, a novel, or something else.

(Shortform note: Another practice that commonly helps people experience and enjoy the present is mindfulness meditation. This works because mindfulness really means awareness; mindfulness meditation trains you to be aware of yourself and everything you’re experiencing moment-to-moment. Once you’re aware of those experiences, you’ll be able to appreciate and enjoy them.)

We’ve Evolved to Neglect ‘What Is’

Lieberman and Long say that unfortunately, humans haven’t evolved to be happy; we’ve evolved to survive, and survival is largely dopamine-driven. Early humans had to constantly search for what they needed to live, such as places to take shelter and animals to hunt. Taking the time to relax and enjoy what they already had wouldn’t have helped them survive. We’ve already discussed the effects this has at the individual level: the urge to chase whatever you don’t have, regardless of whether you really need it, or even whether it’s good for you.

At the societal level, that same urge has both positive and negative effects. On the positive side, it drives humanity to constantly seek new discoveries, new inventions, more territory, and more resources. This leads to incredible advancements in science and technology.

(Shortform note: The authors make the case that the human drive for progress and discovery is at least partly the result of genetics; we’ve evolved to produce large amounts of dopamine and to feel motivated because of it. In that case, all of human civilization—including our countless inventions and the fact that we’re found all over Earth—is arguably part of what biologist Richard Dawkins (The Selfish Gene) calls the extended phenotype. “Phenotype” typically means all of an individual’s physical traits, such as height and hair color. However, Dawkins extends the definition of phenotype to include the ways an individual affects the world. Since our genes drive us to discover, invent, and produce, Dawkins might argue that everything we create is part of our phenotype.)

However, Lieberman and Long say that human urges have also had terrible consequences for the planet—for instance, pollution, overuse of resources, and global climate change. Therefore, if we don’t find the right balance between “what if” and “what is,” the same dopamine-driven habits that kept our ancient ancestors alive could end up wiping us out.

Evolution: Survival of the “Good Enough”

It might seem strange that we’ve evolved into a species that’s able (and, at the moment, apparently likely) to destroy our planet and therefore ourselves. If we’ve evolved to survive, isn’t that counterproductive? However, evolution isn’t intelligent, and it can’t plan ahead—evolution simply means that organisms who are able to survive and reproduce in their current environment will do so.

While evolution is commonly framed as survival of the fittest, some biologists argue that it would be more appropriate to call it survival of the adequate. In other words, evolution doesn’t try to create some hypothetical perfect species. Instead, it’s simply the process of “good enough” organisms creating more “good enough” organisms.

Even though our dopamine-driven habits might prove self-destructive in the long run, they’re helping humanity to survive and reproduce right now. Therefore, the genes that produce those habits continue to pass from generation to generation. As a result, humanity keeps overusing Earth’s resources and degrading the environment, despite knowing the potential harm it could cause.