Living with Our Genes

Living with Our Genes: Why They Matter More Than You Think (1998) by Dean Hamer and Peter Copeland is a nonfiction study of genetics. The book is credited with making a complicated and difficult subject easy to understand and fun to read about but has also been accused of gratuitous gender stereotyping in the anecdotal examples, particularly in the chapter about sex.

The book seeks to add to the age-old Nature vs. Nurture debate, by arguing for the influence of our genetic make-up on the way we react to emotions like anger or fear, addiction, thrill-seeking, sex, and more. The debate is far from resolved; Hamer and Copeland obviously fall into the camp of genes (Nature), but shy away from biological determinism. In fact, the entire argument of the book seemingly hinges on Nature and Nurture working together (24): temperament might determine the choices we make that place us in environments that, to greater or lesser degrees, shape our character (14). Sometimes this diffidence comes across as contradictory or confusing.

Core to their argument is the idea that temperament and character are the two fundamental building blocks of personality. They hold to the belief that “you have about as much choice in some aspects of your personality as you do in the shape of your nose or the size of your feet” (7). In other words, temperament is our natural inclination towards behaviors; we might be able to self-modify to an extent, but we all have different hardwired responses to situations and stimuli. Hamer and Copeland point out that there’s a fair amount of disagreement over temperament because the blank slate theory is attractive and we “want to believe that we can remake ourselves into anything we want, even when our attempts repeatedly fail” (8). Their definition of character involves the belief systems, self-awareness, and ability to recognize our own behaviors and deal with them appropriately. They use the example of politeness to illustrate the difference between temperament and character. The hardwired gut reaction to someone you don’t like might be to avoid them, but in a social situation where that would be uncouth or difficult, displaying politeness is a sign of character.



Part of their research pulls on twin studies. Identical twins are genetically the same, whereas fraternal twins are only as alike as regular siblings, they just happen to be born at the same time. They also studied sets of twins who were raised together, as well as sets who were separated at birth and adopted by families from different economic backgrounds. The evidence presented by the twin studies of Jim  Lewis and Jim Springer, and of Amy and Beth (both twin sets raised apart and who yet were startlingly similar in temperament and life choices) revealed that “genes not only help determine the way we look, but how we act, feel, and experience life. In case after case discovered by researchers, nature won out over nurture” (22). Yet, Hamer and Copeland argue that studying genetics is not a forced march of Calvinist predestination, but is actually liberating because it helps us understand our own genetic programming and how to modify behaviors.

For example, in the chapter for addiction, Hamer and Copeland argue that genes influence both the decision to use drugs or alcohol, and how individual bodies are affected by those substances. For instance, they discuss prealcoholics, whose genetic predisposition to alcohol means that their bodies lack a biological brake that prevents most people from eating or drinking too much; in fact, for a prealcoholic, consumption of alcohol leads to a greater craving for more and an initial higher tolerance for more (143-144). In their discussion about who becomes an alcoholic, they summarize research done in the United States and Sweden: biological offspring of alcoholics have a higher risk of alcoholism even if they are separated from their alcoholic parents at birth, whereas offspring of non-alcoholics who were raised by alcoholics did not have an increased risk (142). Furthermore, they distinguish between two kinds of alcoholic: Type I, which affects women and men equally, and usually manifests in middle age; and Type II, which skews towards young males and is connected to bingeing and aggression. The former type tends to be environmental, whereas research suggests that Type II is usually genetic (142).

In the conclusion, Hamer and Copeland discuss the future of genetic research and the possible benefits. They mention the Human Genome Project, which argues the premise that if we can map our genome, we will also be able to produce new drugs targeted to specific individuals, reduce or eradicate birth defects or genetic disorders, and overall live longer and healthier (300). Hamer and Copeland also wonder how behaviors might be adjusted or mitigated with gene therapy, as well. They argue for genetics as a tool for diagnosing or pre-diagnosing specific illnesses. Instead of relying solely on a fallible human doctor’s powers of observation, they argue that by using a device called a DNA chip, doctors will be better able to diagnose and treat illness. But they also mention that gene mapping could also affect things like insurance premiums, employment opportunities, dating, military selection, and marketing. They mention that “[w]e will have all new ways to understand people—and to label them, discriminate against them, or help them. The technology is coming; how to use it is up to us” (303). They also point out that gene therapy has its limits. Adjusting one person’s genes to mitigate a certain behavior or disorder might work for the individual, but it only works on the person, not the potential offspring.