The Molecule of More

Psychiatrist Daniel Z. Lieberman and writer Michael E. Long argue that human behavior is governed by the interplay between two neurochemical systems. Their central framework rests on a spatial metaphor: looking down represents peripersonal space, the realm of things within arm's reach that can be touched and enjoyed right now, while looking up represents extrapersonal space, everything beyond one's grasp that requires planning and effort to obtain. A group the authors call the Here and Now molecules, or H&Ns, including serotonin, oxytocin, endorphins, and endocannabinoids, govern present-moment satisfaction. Dopamine, by contrast, drives the pursuit of things not yet possessed. It is the molecule of anticipation, possibility, and perpetual dissatisfaction, and humans produce more of it than any other creature.

The book opens with love, using a fictional couple, Shawn and Samantha, to illustrate how dopamine fuels romantic passion and why that passion inevitably fades. The authors trace dopamine's 1957 discovery by researcher Kathleen Montagu and recount how early experiments with cocaine led scientists to label it the "pleasure molecule." That label collapsed when subsequent studies found that dopamine activity shut down after repeated rewards, even though subjects still enjoyed them. Neuroscientist Wolfram Schultz's experiments with macaque monkeys established that dopamine responds not to pleasure itself but to surprise and anticipation. The authors introduce reward prediction error, the difference between what is expected and what actually occurs, as dopamine's true trigger. This mechanism explains why love fades: As a partner becomes familiar, dopamine shuts down. For love to endure, it must transition from dopamine-driven passionate love, which anthropologist Helen Fisher estimates lasts twelve to eighteen months, to companionate love mediated by H&N chemicals, particularly oxytocin and vasopressin.

The discussion of addiction builds on this framework. Addictive drugs hijack the dopamine desire circuit, a neural pathway running from the ventral tegmental area, a dopamine-producing region deep in the brain, to the nucleus accumbens, a region that helps generate motivation and desire. These drugs stimulate the circuit far more intensely than any natural reward and, unlike food or sex, have no satiety mechanism. The speed at which a drug reaches the brain determines the size of the dopamine surge, which is why smoking crack cocaine is more addictive than snorting powder cocaine. Over time, the brains of people with addiction lose the capacity to produce a high, yet they continue using to relieve the anguish of dopamine shutdown rather than to experience pleasure. Psychologist Kent Berridge's research demonstrated that wanting and liking are produced by separate brain systems: Boosting dopamine in rats increased consumption but not signs of enjoyment, while boosting H&N chemicals tripled the pleasure response. This disconnect explains why people with addiction pursue substances they no longer enjoy.

The authors then introduce the dopamine control circuit, a second dopamine pathway running to the frontal lobes, the brain's center for logical thinking and long-term planning. While the desire circuit generates raw wanting, the control circuit evaluates options, constructs strategies, and exerts willpower. Experiments at the University of Connecticut demonstrated that dopamine drives tenacity rather than the subjective value of a reward: Rats depleted of dopamine would not work harder for food as effort requirements increased. The control circuit also powers self-efficacy, the confident expectation of success that can function as a self-fulfilling prophecy. The authors illustrate the costs of extreme dopaminergic dominance through astronaut Buzz Aldrin, whose post-lunar struggles with depression and strained relationships exemplified the inability to experience present-moment fulfillment after achieving the ultimate goal. At the other extreme, attention deficit hyperactivity disorder (ADHD) represents a weakness of the control circuit, particularly in children whose frontal lobes have not yet fully developed. Paradoxically, treating ADHD with stimulant medications strengthens the control circuit and reduces the risk of later substance use.

Willpower, the authors argue, is a depletable resource. In the famous radishes-and-cookies experiment, participants who resisted freshly baked cookies and ate radishes instead gave up on a subsequent task in less than half the time of those who ate cookies freely. Because willpower alone cannot sustain long-term change, the authors describe three evidence-based addiction therapies. Motivational enhancement therapy pits desire against desire by strengthening patients' healthy wishes for a better life. Cognitive behavioral therapy uses the control circuit's planning ability to anticipate and avoid craving triggers. Twelve-step facilitation therapy harnesses H&N social bonds and the emotional weight of guilt to oppose dopaminergic craving.

The chapter on creativity argues that creative genius and mental illness share a common dopaminergic root in the brain's salience-detection system, which marks things as important. When this system misfires and attaches significance to ordinary events, it produces the delusions of schizophrenia. When it operates in a controlled way, breaking apart conventional models to reveal unexpected connections, it produces creativity. The authors identify low latent inhibition, the failure to filter out familiar stimuli as unimportant, as the shared mechanism linking the two conditions. An Icelandic study of over 86,000 people found that carriers of genes associated with schizophrenia or bipolar disorder were more likely to belong to national societies of artists. The authors note that highly dopaminergic figures, from Albert Einstein to Beach Boys musician Brian Wilson, often contended with strained relationships, mental illness, or both.

Applying the framework to politics, the authors argue that liberals tend to have more active dopamine systems, making them risk-taking, novelty-seeking, and future-oriented, while conservatives tend to have stronger H&N systems, making them empathic, conventional, and stability-oriented. Evidence includes brain-scan research demonstrating greater mental flexibility among liberals and the concentration of liberal ideology in dopaminergic environments like Silicon Valley, Hollywood, and academia. Conservatives give more to charity at every income level, are more likely to marry, and are less likely to be unfaithful. The authors explain loss aversion, the phenomenon in which the pain of losing something exceeds the pleasure of gaining it, as amplified by the amygdala, an emotion-processing brain region that intensifies the distress of loss. Even subtle environmental cues shift political orientation: Placing a hand sanitizer near survey respondents increased conservative attitudes, while asking conservatives to imagine being invulnerable made them more liberal.

The chapter on progress traces how dopaminergic genes shaped human migration and national character. Researchers found that populations who migrated farther from Africa had higher frequencies of the 7R allele, a long variant of the DRD4 dopamine receptor gene associated with novelty-seeking and risk-taking. The United States, populated almost entirely by immigrants, has the world's highest rate of bipolar disorder, a condition characterized by episodes of depression and mania, at 4.4 percent, compared to 0.7 percent in Japan. In Democracy in America, French political thinker Alexis de Tocqueville described 19th-century Americans pursuing improvement with restless energy and traveling vast distances to "shake off his happiness" (195). Americans received 42 percent of all Nobel Prizes between 1901 and 2013. The chapter warns that dopamine's relentless drive for more now threatens humanity through nuclear weapons, climate change, uncontrollable artificial intelligence, and demographic collapse as career and consumption replace child-rearing.

The final chapter argues that fulfillment requires balancing dopamine and H&N. The authors advocate for mastery, the state in which dopamine, having achieved its goal, pauses and allows H&N satisfaction to emerge. They recommend paying full attention to present reality, citing Harvard research showing that a wandering mind consistently correlates with unhappiness. Creative activities combining intellectual planning with physical making, such as woodworking, cooking, and gardening, blend dopamine and H&N into more durable satisfaction. The book concludes that while dopamine circuits define much of what we consider uniquely human, identifying exclusively with dopamine traps us in a world of unrealized possibilities. True well-being requires integrating dopaminergic imagination with sensory experience, emotional engagement, and the appreciation of what is already here.