May 30, 2021

green separator

Genes, germs, and the curious forces
that make us who we are.

by Bill Sullivan.
National Geographic,
2019 (335 pages)

green separator
green separator
    Quote = "Working in the biological sciences for the past 25 years has provided me with a unique perspective on how life truly operates. My research into the hidden forces underlying our behavior has convinced me that almost everything we think we know about ourselves is wrong. And we are paying dearly for it. Our false sense of self hurts our personal, professional, and social lives." (By Bill Sullivan, author of the book, page 14)

    Quote = "Our collective misunderstanding of human behavior impedes progress and adversely affects education, mental health, our justice system, and global politics. Exposing these hidden forces provides important new insights into our behavior, as well as a better understanding of people who do things we would never dream of doing." (By Bill Sullivan, author of the book, page 14)

    Quote = "A little autonomy is sacrificed for the greater good. But because individuals (and their kin) often benefit from that greater good, it forms a positive feedback loop." (By author Bill Sullivan, page 298)
green separator

note = Numbers in parentheses refer to pages

INTRODUCTION --- Meet the real you (9-15)
    note = "Scientists have recently learned a great deal about us: deep, dark secrets that everyone needs to know. The better you know your true self, the easier it is to navigate life's journey. And, by knowing what makes people tick, you will have a better understanding of those who are not like you... If we were not in control of something as basic as our personal tastes, what other things about us are beyond our command?" (11)

    note = "In these pages, I set out on a quest to see how much genes contribute to our behavior. As we will see, DNA presides over much more than our physical attributes like eye color and whether we were born with hands. It can also influence what we do with our lives, how quickly we lose our temper, whether we crave alcohol, how much we eat, who we fall for, and whether we like to jump out of perfectly good airplanes. DNA is often referred to as the ‘blueprint of life' because it contains the instructions to build an organism... In this book, we will take a look at the factors in our environment that can affect how our genes work, as well as how the environment may alter our DNA in ways that might be passed on to future generations. The means by which the outside world interplays with our genes is a new field of study known as epigenetics. Epigenetics can have a tremendous impact on our behavior and, remarkably, its effects on our DNA begin before we were born." (11-13)

    note = "For example, exposure to nicotine or other drugs may chemically alter genes in the sperm of a father-to-be. What a mother does during pregnancy can also introduce lifelong changes onto the baby's DNA. Epigenetics may play a wide-ranging role in obesity, depression, anxiety, intellectual ability, and more. Scientists are discovering how stress, abuse, poverty, and neglect can scar a victim's DNA and adversely affect behavior for multiple generations. These astonishing findings in epigenetics constitute another hidden force directing our behavior, over which we have also had zero control." (13)

    note = "In addition to our own genes, scientists have recently recognized that microscopic invaders bring a massive repository of genes into our bodies that are likely to shape our behavior as well. Ever hear of a microbiome?... The first microbial stowaways to set up camp in our gut came from our mother. We pick up more microbes from our food, pets, and other people as we age. New studies are revealing that the trillions of microbes teeming inside our guts may exert an influence on our food cravings, mood, personality, and more. For example, scientists can make a normally perky mouse gloomy by replacing its intestinal bacteria with microbes taken from a person suffering from depression." (13)

    note = "We will examine how the western diet many of us enjoy radically changes the composition of gut bacteria, leading some to speculate that it could be a contributing factor to health problems like allergies, depression, and irritable bowel syndrome, which are more common in affluent countries. There is also a one in four chance that a common parasite transmitted by cats... that we study in my labor story might have hijacked your brain, dampening your cognitive abilities and predisposing you to addiction, rage disorder, and neuroticism. We will discuss emerging evidence suggesting that all of these tiny microbes are affecting our behavior for their benefit, making us wonder yet again if we are really in full control of our actions." (13-14)

    note = "In the upcoming chapters, we will take a closer look at just how much — or really, how little — control we have over our actions. This knowledge will help us better ourselves, and has the power to change our behavior in ways that will lead to a happier and healthier world. We will learn the real reasons why some people become aggressive or murderous, revealing potential ways to prevent these hideous behaviors from occurring. We will also explore what science is teaching us about love and attraction, and how these lessons can improve our relationships. And finally, we will peer into the psychology of our beliefs, including our political differences, in hopes that we can understand what leads us to act with blind faith, rather than insightful reason." (14-15)
1) MEET YOUR MAKER (17-34)
    [1] Why you can't be whatever you want to be (21-24)

    [2] How your environment affects your genes (24-29

    [3] How microbes add to your genes (29-32)

    [4] Why our maker is in trouble (32-34)

      note = Who is your real "maker"?
    [1] Why you hate broccoli (36-39)

    [2] Why you love broccoli (39-40)

    [3] Why you love junk food (41-43)

    [4] Why you think Cilantro tastes like soap (43-45)

    [5] Why you like it hot (45-49)

    [6] Why you can't live without coffee (49-52)

    [7] Why milk doesn't do every body good (52-54)

    [8] Why you think the $40 bottle of wine tastes better (54-58)

      note = Use "retronasal passage" to explain taste and aroma convergence and the impact of a long, passionate kiss, on whether wine tastes the same by both people (55)

    [9] How you can eat something so disgusting (58-60)

    [10] Living with your tastes (60-61)
    [1] Why you crave the high [calorie] life (65-68)

    [2] Why you eat too much (68-72)

    [3] How your parents influenced your appetite (72-77)

    [4] Why sugar might make your life sweeter, but shorter (77-78)

    [5] How your gut bacteria might be swaying your appetite (78-82)

    [6] How you might be able to change your cravings (82-86)

      note = use bacteria influencing brain and behavior (85)

    [7] Why you don't have an appetite for exercise (86-89)

    [8] Food for thought (89-91)
    [1] Is alcoholism in your genes? (95-99)

    [2] Why some people just say no (99-101)

    [3] Why alcohol hits some harder than others (101-102)

    [4] Why it's so hard for some people to stop drinking (102-106)

    [5] Why don't do drugs? (106-112)

      note = reference to book, Unbroken Brain (111)

    [6] Why you engage in risky business (112-117)

    [7] What a long, strange trip it's been (117-119)
5) MEET YOUR MOODS (121-151)
    [1] Where your feelings come from (122-127)

    [2] Why you seem down in the dumps all the time (127-131)

    [3] How your childhood shapes your mood (131-135)

    [4] How your gut affects your mood (135-138)

    [5] Why there are grumpy old men (138-139)

    [6] Why you get the winter blues (139-141)

    [7] How carbs can make you giddy (141-143)

    [8] Why there are shiny happy people (143-145)

    [9] Why happiness might not be all it's cracked up to be (145-148)

    [10] Clap along if you know what hapiness is to you (148-150)

    [11] Awakenings (150-151)
6) MEET YOUR DEMONS (153-184)
    [1] Why you get scared (154-156)

    [2] How your grandparents' demons may be haunting you (156-160)

    [3] Why man's demons are from Mars, woman's demons are from Venus (160-164)

    [4] Are demons hiding in your genes? (164-168)

    [5] How your childhood demons affect you in adulthood (168-174)

      note = What epigenetics shows us (169-172)

      note = Charles Whitman and the tumor that pressed up against his amygdala, the part of the brain region critical for regulating fear and anxiety (175-176)

    [6] How brain invaders drive you mad (174-178)

    [7] Is there a devil inside us? (178-181)

    [8] Should we feel sympathy for the devil? (181-182)

      note = use last paragraph (182)
7) MEET YOUR MATCH (183-216)
    [1] Why it takes two, baby (184-186)

    [2] Why we're so superficial (186-190)

    [3] Why love stinks (190-194)

    [4] Why opposites attract but don't usually last (194-196)

    [5] Why young love feels so different from old love (196-200)

    [6] Are we monogamous? (200-203)

    [7] Why we stay together (203-208)

      note = Insel and prairie voles = oxytocin and vasopressin (205-208)

    [8] Why are some people attracted to the same sex? (208-213)

      note = "It is now well established that gender identity is separate from a person's anatomical sex --- what's below the belt does not matter if the head thinks it owns the opposite equipment. There is a critical period during fetal development when hormones shape the brain into a male or female form, or perhaps something in between those two ends of the spectrum." (212)

    [9] Do we have a soul mate? (213-215)

    [10) Almost paradise (215-216)
8) MEET YOUR MIND (217-240)
      Quote = "If the human brain were so simple that we could understand it, we would be so simple that we could not!" (By Emerson M. Pugh in his book The Biological Origin of Human Values, page 217)

      Quote = Hippocrates, Galen, Aristotle, Leonardo da Vinci (218)
    [1] What's in your brain? (219-222)

    [2] Why your brain has issues (222-224)
      note = Does your brain get squirmy, like Linus w/o his security blanket? (223)
    [3] Why you do things for no good reason (224-228)

    [4] Why some people are so smart (228-232)

    [5] Is there a genius sleeping inside your brain? (232-234)

    [6] Why we forget things (234-239)

    [7] Why you are an illusion (239-240)

      note = Why is the human essence of you reality: and not an illusion? [Question posed by webmaster and answered everywhere on this website]

      note = "The decision-making process seems to be as involuntary as our heart rate and breathing. As mentioned, a primary function of the brain is to simulate our reality to bring the world ‘out there' into our skull so our brain can respond. It would appear that what we call our ‘self' is just another character in this facsimile, and that our brain knows what we are going to do before we do." (240)

      note = "If this is true, our sense of self and free will are illusions. Before your head spins right off your shoulders and you go to bed thinking that no one is accountable for anything, there is a school of thought that argues that instead of free will, we have ‘free won't.' Although we do not have control over the decisions our subconscious makes, some researchers argue that our conscious brain has veto power. In other words, our subconscious is like Congress drafting bills and our conscious brain is the president. We have no free will in which bills cross our desk. But we can decide which ones are sent to the recycle bin. Free will or free won't, the truth is:" (240)

        Quote = "Life does not require a brain, but a brain makes life worth living!" (240)

    9) MEET YOUR BELIEFS (241-268)

      [1] Why most of us are not rebels (242-245)

      [2] How groups become polarized (245-247)

      [3] Why political arguments make you want to pull out your hair --- or their hair (247-253)

      [4] Why is it hard --- but not impossible --- to change their mind? (253-256)

      [5] Why we're religious (256-261)

      [6] Dude, where's my soul? (261-267)

      [7] What should we believe? (267-268)

    10) MEET YOUR FUTURE (269-294)

        Quote = "The more we understand our nature, the better we will be at nurturing." by Steven Johnson (269)

      [1] How we can change our genes (271-275)

      [2] How we can change gene expression (275-280)

      [3] How we can take control of our microbial guest list (280-284)

      [4] How we can hack our brain (284-290)

      [5] Why we need to live an evidence-based life (290-294)

        note = Discovery of germs in mid-1800s (291)

        note = "Science has dispelled the idea that anyone can be anything they want to be; great disparities in nature and nurture put us on a vastly unequal playing field. But we can take practical measures to minimize these disparities and help everyone live to their full potential. When it comes to our fellow human beings, especially our children, the choice should not be sink or swim; it should be swim or be rescued." (293-294)

        note = "Informed by our biology and guided by evidence, we can build better environments for all. This will lead to a stronger and healthier society." (294)

    CONCLUSION — Meet the new you (295-298)

      note = "Instead of condemning people, Let us try to understand them. Let us try to figure out why they do what they do. That is a lot more profitable and intriguing than criticism. It breeds sympathy, tolerance, and kindness." (By Dale Carnegie in his famous book, How to Win Friends and Influence People). (295)

      note = "Nothing explains everything, meaning that there is never a single explanation for our behavior. Nor can our success and failures in life be attributed solely to our awesomeness or lack thereof. Our actions and personalities arise from a dizzying interplay between genes (including how they have been epigenetically programmed), microbes, hormones, neurotransmitters, and our environment. We also cannot view our present behavior without recognizing the dirty fingerprints left behind by the evolutionary pressures that shaped us --- especially the intense subconscious drive to survive and reproduce." (295)

      note = "After all these years of thinking we were free agents, we have come to realize that most, if not all, of our behavior is not of our own volition. It has been guided and restricted by puppet strings. One string is DNA. Another is epigenetics. Another is our microbiota. Yet another is our subconscious. And we are discovering more strings that tug on our behavior in ways still unbeknownst to us. For example, when a gene is transcribed into a protein, the genetic instructions are carried on a molecule called messenger RNA (mRNA), which can also be chemically modified like DNA can be methylated. The study of chemical modifications on mRNA is called epi-transcriptomics, and these changes affect how much protein is made from the mRNA and when." (296)

      note = "Proteins themselves can also be chemically modified in ways that alter their stability, function, or location in a cell. All these additional regulatory steps make it harder and harder to predict someone's behavior solely on their gene sequences. Once concealed from our view, the puppet strings that have been controlling us are now visible. More than that, we are discovering potential ways to cut the cords through gene editing, epigenetic drugs, remodeling microbiomes, and merging brains with computers. The hand of fate that has served as our puppet master has been evolution. But like a puppet that has learned to be its own puppeteer, science has provided us the ability to evolve ourselves." (296-297)

      note = "Only time will tell whether humanity's puppet show will be a hit or a flop. We stand a better chance of success if we allow history to serve as our Jiminy Cricket. Human nature was born from selfish genes, but selfish genes are so yesterday. The disease of selfish genes continues to plague our species in the form of inflated egos, greed, dishonesty, cheating, the creation of ‘us versus them' dichotomies, and the tolerance of a social hierarchy that allows the world's riches to be restricted to a few alpha males while billions wallow in poverty." (297)

      note = "These selfish genes created the 'diva' part of the brain: the part that almost always gets us into hot water or causes suffering in others. But these genes have also created a brain that devised the scientific method as a means to better understand itself and the universe it inhabits. Over the ages, from astronomy to zoology, science has been taking us off the pedestal upon which the diva brain has perched itself... Egos put up unnecessary walls between the folks we consider to be on our team and the other people in the World. The demolition of the ego will help us erase the nonsensical lines dividing us, turning fists into open hands. History has proven that cooperation is infinitely more beneficial for individuals and society at large. Species that learn to team up and divide labor are mimicking what individual genes did long ago when they came together as a team in DNA." (297)

      note = "A little autonomy is sacrificed for the greater good. But because individuals (and their kin) often benefit from that greater good, it forms a positive feedback loop. The vast majority of nature is red in tooth and claw, with no regard for the welfare of others. But some species have flipped this logic on its head. We have done so to the greatest extent, where a lack of compassion is now considered a psychological disorder. This ‘scratch my back and l will scratch yours' strategy has served us well and is the key to future prosperity.

      note = Helping people regardless of their genetic equivalency to us is the ultimate rebellion against selfish genes. By defying the primitive urges of me, me, me, we can flip off the selfish genes and live a life of human nurture, rather than human nature. I think we are all up to the challenge." (298)


    SELECT SOURCES (302-329)

    INDEX (330-335)
      Genetic engineering
      Gut bacteria
      Love and romance
      Politic beliefs
      Russell, Bertrand
      Sperry, Roger
      Taste preferences
      Violent behavior
    green separator

    green separator

    AUTHOR NOTES = Bill Sullivan is a professor of pharmacology and microbiology at the Indiana University School of Medicine in Indianapolis, where he studies infectious disease and genetics. He has published nearly 70 peer-reviewed scientific journals and textbooks. He obtained his doctorate in cell and molecular biology from the University of Pennsylvania and has been praised in student evaluations for making lectures on antibiotics "wildly entertaining." As an award-winning researcher, teacher, and science communicator, he has published dozens of papers in scientific journals and has written for National Geographic, Discover, Scientific American, Scientific American MIND, COSMOS, Psychology Today,, A Science Enthusiast, and more.

    Sullivan has been interviewed by CNN, Scientific American, Cosmos magazines, PLOS SciComm, The Naked Scientists, he Scientist. the Wall Street Journal, The Indianapolis Star, Science Fantastic with Dr. Michio Kaku, The Naked Scientists, The Scientist, and more. He has given a variety of science-related talks at schools and libraries, and participated at events including PopCon, GenCon, Starbase Indy, and Pint of Science. He lives in Indianapolis, Indiana, with his wife and two children. Visit him at

    SUMMARY = "I can't believe I just said that." "What possessed me to do that?" "What's wrong with me?" We are constantly seeking answers to these fundamental human questions, and now, science has the answers. This witty, colloquial book is popular science at its best. It describes in everyday language how genetics, epigenetics, microbiology, and psychology work together to influence our personality and actions. The book is a life-changing look at what makes you who you are. It is filled with fascinating insight from a witty new voice in popular science.

    BOOK DESCRIPTION = Clever, relatable, and revealing, this eye-opening narrative by Indiana University School of Medicine professor Bill Sullivan explores why we do the things we do through the lens of genetics, microbiology, psychology, neurology, and family history. From what we love (and hate) to eat and who we vote for in political elections to when we lose our virginity and why some people find drugs so addicting, this illuminating book uses the latest scientific research to unveil the secrets of what makes us tick. The book explains how experiences that haunted our grandparents echo in our DNA; why the bacteria in our guts mess with our minds; and whether there really is a "murder gene." Why are you attracted to a certain "type?" Why are you a morning person? Why do you vote the way you do? From a witty new voice in popular science comes a clever, life-changing look at what makes you.

    The foods we enjoy, the people we love, the emotions we feel, and the beliefs we hold can all be traced back to our DNA, germs, and environment. How do the experiences that haunted our grandparents echo in our DNA; why do the bacteria in our guts mess with our minds; and is there really a "murder gene." In addition: "Why are you attracted to a certain "type?" "Why are you a morning person? Why do you vote the way you do? The book mixes cutting-edge research and relatable humor to share fascinating insights that shine a light on who we really are — and how we might become our best selves. This revolutionary book explains the hidden forces shaping who we are and points us on a path to how we might become our best selves.

    green separator
    green separator

    BOOK LIST REVIEW = The ambitious aim of this book, to elucidate Why we are who we are and do the things we do, rings a bit like a 1970s song lyric and, frankly, seems unattainable. But Sullivan, a professor of microbiology and immunology, gives it the old college try. He explains how human behavior, actions, and personality arise from a complex interplay between genes, epigenetics (the effect of environment on our genes), hormones, neurotransmitters, our evolutionary history, environment, our microbiota (the trillions of microorganisms living on and inside us), and culture. He examines how these many factors and forces contribute to moods and phobias, sex and love, taste and appetite, brain and mind, addictions and beliefs (religious and political). The scientific discussion is enlivened by Sullivan's quirky sense of humor and frequent nods to pop culture. Unusual (and sometimes unsettling) information, such as that about one-third of persons are infected by a single-cell parasite, Toxoplasma gondii, transmitted by cats or acquired from contaminated food or water, is plentiful. Humans' only innate fears are of falling and loud, unanticipated noises. Intriguingly informative.– Tony Miksanek.

    green separator
    green separator

    [1] In equal parts approachable and mind-blowing. Sullivan gives us a whistle-stop tour of the myriad factors that make you who you are" -- David Eagleman, author of many books about the brain and host of PBS's The Brain by David Eagleman.

    [2] From microbes that make you intoxicated to the genetic demons hiding within your DNA, this book is a whirlwind journey through human biology. Deftly weaving cutting-edge science with popular culture, this accessible book will leave you wanting more. -- Sharon Moalem, PhD author of the book, Survival of the Sickest.

    [3] A rare treat: A book that's fun to read from cover to cover, while leaving you wiser and better-informed about who you really are. -- Adam Alter, New York Times bestselling author of the books, Drunk Tank Pink and Irresistible.

    [4] Bill Sullivan is a sympathetic guide who understands your dislike of exercise and most things healthy. This wide-ranging tome puts a new light on human pursuits, including eating, drinking, thinking, sex, free will, even politics and religion, all presented with topical humor and wit. -- Scott Anderson, co-author of The Psychobiotic Revolution.

    [5] Bill Sullivan artfully reports on how our genes interact with our surroundings to shape our unique personalities and the people we have become. A beautiful melding of science and the human experience. -- Peter Hotez, MD, PhD, author of the book, Vaccines Did Not Cause Rachel's Autism.

    [6] Pleased to Meet Me is as close to philosophy as science books get. Infused with Sullivan's witty voice, the book exposes us as the biological machines we really are. You'll be quoting it to your friends. -- Dr. Alanna Collen, author of the book, 10% Human.

    [7] Pleased to Meet Me makes you see the world in a new way. We like to think we're totally in control of how we think and act, but Sullivan makes a strong case that our beloved ‘agency' is not what we think it is. -- Matthew Simon, Wired blog and science magazine writer and author of the book, Plight of the Living Dead.

    [8] Filled with surprising facts, witty anecdotes, and engaging explorations of the biological forces that make us who we are, the book is a must-read for anyone interested in an intelligent approach to self-discovery. Bill Sullivan translates cutting-edge science into practical insights about the ways that genes, germs, and environment shape our health, happiness, and relationships. This delightful book will change the way you see yourself — and will provide newfound empathy for others. -- Ty Tashiro, author of the book, Awkward and The Science of Happily Ever After.

    [9] A book for everyone with an interest in human behavior, the book achieves the rare feat of presenting of scientific information that is also fun to read. Not only will your knowledge be greatly enhanced, but you are more likely to become more compassionate as well." -- James E. Alcock, PhD, author of the book, Belief.

    [10] Can scientists be humorous as well as informative? Bill Sullivan has created an amazing book that easily communicates the science of human biology while providing examples that allow even a beginning science reader to approach this book. He combines the art of storytelling with hard science in ways that provoke thought and reflection. If you want to know more about how your body interacts with the biological world this is your book. -- Mark D. Kesling.

    green separator
    You Are Your Adaptable Memory!
    green separator

    Click or Tap Star to Return to Humanist Galaxy

    Bill Sullivan


    Alphabetical Brain Vocabulary

    green separator
    produced by
    Infinite Interactive Ideas™