For most of human history, people lived in pretty much the same way. No one was born in a hospital, because there were no hospitals. There was no such thing as organic farming, because there were no synthetic pesticides. Nothing was made of plastic. There were no microwaves or cell phones or airplanes or antibiotics or energy drinks. Not coincidentally, no one worried about these things. There were, of course, lions and tigers and bears, but our relationship to these animals was more straightforward. Overall, the potential threats, while arguably much greater in magnitude, were much easier to identify. But as the ever more numerous miracles of technological innovation continue to improve our lives, they also make it more complicated. Now, not only do we have things we didn’t have before, we know things we didn’t know before. There are clearly some things to worry about, but what are they? News media, social media, and every mom blog in the world will give you plenty of things to put on your list of worries. At the same time, there are many more places to get information than there have ever been. When these sources conflict, whom should you trust? As we struggle to make healthy and responsible choices for ourselves and our families, all of this ambiguity can be very stressful.
Here’s the thing: stress, in and of itself, can cause health problems. Chronic stress can lead to digestive complaints, sleep problems, headaches, depression, irritability, high blood pressure, cardiovascular disease, diabetes, and stroke. It can also suppress your immune system so that you are frequently ill and make you look haggard and prematurely old. You can treat some of these symptoms with medication, but it would be much better to treat the underlying cause of the problem. Namely, it would be better to stop being so worried. There are a few things that can help. For example, some people find that regular exercise, meditation, or prayer helps them cope. These approaches might help with your stress level, but they don’t address the underlying problem, which is that there are lots of potentially dangerous things in the world. But there is another complementary approach you can try, and that is to take control of the situation.
In this case, taking control means critically evaluating potential threats, determining what poses the greatest danger, and prioritizing your actions to minimize adverse outcomes. Knowledge is power. This is a good strategy because a sense of personal control is associated with positive mental health and lower levels of anxiety and depression. At the same time, you will reduce your overall risk of harm. It’s a two-for-one deal.
The central task then becomes evaluating potential threats, which can be difficult. The world is a complicated place and becoming more complicated all the time. Unfortunately, evolution did not prepare your brain for the world it lives in. Humans tend to be tribal; we trust members of our own groups more than we trust outsiders. In addition, we are motivated much more strongly by stories than we are by statistics. These features were highly adaptive when most of us lived in small family groups, and they are still important today. But these instincts can also lead us to make bad decisions when they are applied to complex issues. Science is here to help, but only if you understand how to use it.
Science is a tool that helps us to understand why things happen. Further, it helps us predict what will happen in the future. Science is not magic; it is in fact the opposite of magic. There is no mystery about it. Fundamentally, science is a formalized way to evaluate cause-and-effect relationships rigorously. In a way, we are all scientists because babies learn to understand the world through cause and effect. But scientists bring some powerful tools to this fight: controlled experiments and math. A controlled experiment is one that eliminates potential confounds; this allows us to attribute the right cause to the effect. Math, particularly statistics, is how we know whether an effect is likely to be real, or whether we are observing something by mere chance. These points may seem nitpicky, but they allow us to draw appropriate conclusions when our intuitions might otherwise lead us astray. This is not to say that scientists are never wrong. Scientists are people, and people make mistakes and have biases that will sometimes lead to inappropriate conclusions. But the scientific method is a very reliable way to reveal underlying cause-and-effect relationships. If you are skeptical, remember that science is what puts airplanes in the sky, mobile phones in our pockets, and, for most of us, food on our tables.
We, the authors, believe that using scientific evidence is the best way to systematically evaluate potential sources of worry. We are also people living in the same dizzyingly complicated and confusing world as everyone else, and are therefore subject to the same concerns and questions. This is, in fact, what motivated us to write this book. We are both scientists, but most of the topics discussed in this book are outside our area of expertise. In writing this book we relied on our scientific training to identify credible sources, to read and understand scientific publications, and to interpret data. In the following chapters we present our findings in the hope that they will be useful to others, but we do not claim to have the final word on any topic. We are research scientists, not medical doctors; we do not provide any medical advice. If you have medical concerns, you should consult your health care provider. We encourage readers to investigate issues that interest them further.
The selection of topics covered in this book is by no means comprehensive. Indeed, there are so many things one could choose to worry about that this is an impossible task. What all of the chapters have in common is that they discuss ordinary everyday concerns. Some compelling issues have notably been left out. For example, there is no chapter about nuclear war. This is not to say that this should or should not be a real concern, but it is certainly beyond the scope of this book. We have also left some topics like vaccinations and global warming unaddressed. This is not because these issues are unimportant, but because they have been so frequently and thoroughly covered elsewhere. Of course, some things have been left out simply for lack of space and time. If, for whatever reason, you do not find the topic that you are looking for covered in this book, or if there is something you would like to know more about, we encourage you to research it on your own. In Appendix A (Do-It-Yourself) we have some suggestions about how to undertake this task.
For each topic that we cover, we have assigned a worry index. This is a way to quickly understand the relative risk posed by each issue. Please recognize that this is a subjective score meant to be illustrative, not definitive. Of course, individuals will have different priorities and may emphasize different factors accordingly. This is absolutely appropriate. In general, we believe that you should only worry about things that are (a) likely to happen, (b) have the potential to do great harm, and (c) can be avoided or mitigated through personal action. You will find that some things are very unlikely to happen, and therefore you can stop worrying about them, as there is no need. There will also be some things that are very likely to happen, but which you cannot stop. You can stop worrying about these things too, as worrying will not help. Finally, there are some things that are likely to happen, but the consequences won’t really be so dire. We recommend that you also stop worrying about these things, because life is short.
We found this book tremendously interesting to write and hope that you will find it interesting to read.