But what really causes addiction? How can one know if they are susceptible to addictions? A child of alcoholic parents or drug-addicted parents worries about whether they can suffer from the same problems. Is this driven by genes, or by the substances themselves? Regardless of the substance, Dr. Lustig says that “they all impact dopamine in some fashion.” Dr. Judson Brewer agrees with this. He describes a process that starts with a trigger. This could be a good or bad event, which is followed up by behavior and followed by a reward. When this is repeated, it becomes a habit or habit loop.

In Dr. Lustig’s book The Hacking of the American Mind, he describes the difference between reward (pleasure) and contentment (happy). The primary thesis of his book is that we confuse the two states; that they are interrelated, but decidedly different phenomena. He lists seven differences between these two phenomena and then ties them into the biological mechanisms supporting these two phenomena. Here is a much abbreviated version of his list.

1. Reward is short-lived; contentment lasts longer. Have you noticed that when you get a promotion or a pay raise, it feels really good at first, but then evaporates—compared to when you complete a very hard project over the course of a few years?

2. Reward is visceral in terms of excitement. Contentment is ethereal and calming.

3. Reward can be achieved with different substances. Contentment is usually achieved with deeds.

4. Reward occurs with the process of taking. Contentment is often generated through giving. (On a related topic, see Paul Zak, “The Moral Molecule: How Trust Works,” for an insightful explanation on the role of oxytocin in human experiences and behaviors such as empathy, altruism, and morality.)

5. Reward is yours and yours alone. Contentment often impacts other people directly and can impact society at large.

6. Reward, when unchecked, can lead us into misery (see stories about lottery winners), like addiction. For the purposes of this book, we are focusing on electronic device addictions.

7. Reward is driven by dopamine. Contentment is driven by serotonin. Each is a neurotransmitter.

You can see by the characteristics in Dr. Lustig’s list that reward tends to be short-lived, alone, substance-driven, and potentially addictive, while contentment activities deal with elegance, giving, community, and doing things for others. The primary reason for referencing Dr. Lustig’s work in a book about Gen Z‑ers at work is in the biochemical mechanisms underlying contentment and reward, and the implications of these two mechanisms for development of the person for being a productive member of society (including family, friends, communities and potential employers). Also, helping others has been known to produce endorphins, also known as a “helper’s high.”

Dopamine and serotonin are neurotransmitters—biochemicals that are manufactured in the brain. These biochemicals drive feelings and emotions and drive separate brain processes. These two biochemicals have separate brain pathways, regulatory schemes, and physiological and psychological outcomes. (For a thorough explanation, see Dr. Lustig’s book.) It’s important to understand how these two chemicals work, and how they work in concert or in opposition to each other. I will tie this in to how and why this is important to our Gen Z cohort.

In order for serotonin and dopamine to carry out their mission, they need the help of something called “transport mechanisms.” These behave like taxi cabs ferrying passengers. The passengers for dopamine are the amino acids phenylalanine and tyrosine. The passenger for serotonin is tryptophan, which is found in eggs, poultry, and fish. The problem with these taxi cabs is that the same cabs are required to transport serotonin and dopamine. The more significant the reward-seeking behavior, the more one is hailing a cab for dopamine. The poor passenger tryptophan is standing on the curb, waiting for an available cab on a cold rainy night. In other words, high use of dopamine will consume the transport mechanisms for serotonin. No serotonin, no experience of contentment.

While these neurotransmitters compete for transport mechanisms, they are very different in terms of regulation. Dopamine receptors (think of receptors as the receiving side of a chemical signal or transaction) are susceptible to something called “down regulation.” Down regulation is more commonly called “tolerance.” When the receptor is continuously stimulated by the presence of dopamine, it can fail to respond to the dopamine, and if stimulation continues, it will eventually die. We see the effects of this in drug addiction. As receptors die off, the addict no longer experiences the effects of the drugs and needs to increase the dosage to achieve the same effects. Unfortunately, as the receptor dies off, dosage increases and a lethal spiral ensues. The primary point here is: constant dopamine-inducing behaviors may lead to tolerance, which can lead to increased dopamine behaviors, which, by definition, may be addiction.