Man is a goal-seeking animal. His life only has meaning if he is reaching out and striving for his goals.
—ARISTOTLE
WE HAVE COME TO THE END OF OUR TOUR OF the science and philosophy of living meaningfully. During the journey we learned about the neurobiology of moral decision-making as well as about John Rawls’s theory of justice, we have examined the hormones that make us fall in love, and we have discussed the ethics of friendship. What we have not examined yet is an assumption underlying this entire book, the same assumption that Aristotle made almost two and a half millennia ago: that there is something fundamental about being human, that we all seek pretty much the same things, though we may arrive (or fail to arrive) at them in a bewildering variety of ways. In other words, that there is such a thing as human nature.
These days the concept of human nature is as unpopular with philosophers as it is intriguing to scientists, and it will be instructive to take a look at both misguided and interesting ways of thinking about it. Perhaps the crassest science-inspired approach to human nature is the one proposed by evolutionary psychologists. Evolutionary psychology, an offshoot of evolutionary biology, is based on the very reasonable assumption that some human behavioral traits have at least a partial genetic basis and have been shaped, in part, by natural selection. As such, the claim is rather uncontroversial, but the devil is in the details. Some evolutionary psychologists are prone to make spectacularly broad claims about human nature that are almost entirely unsubstantiated by the evidence. Just to give you a flavor of what I’m talking about, here is a sampler from Alan S. Miller and Satoshi Kanazawa, whose article in Psychology Today is provocatively entitled “Ten Politically Incorrect Truths About Human Nature”:
Men have built (and destroyed) civilization in order to impress women, so that they might say yes.
Thus, men who prefer to mate with blond women are unconsciously attempting to mate with younger (and hence, on average, healthier and more fecund) women.
Muslim suicide bombing may have nothing to do with Islam or the Koran. . . . As with everything else from this perspective, it may have a lot to do with sex, or, in this case, the absence of sex.
The first statement is ridiculous on the face of it. Every other animal species on the planet has managed to get their females interested in sex without having to design rockets to get to the moon, so it isn’t clear why we would be the exception (or on what bases Miller and Kanazawa have arrived at this bizarre conclusion). The second statement neglects a few obvious facts about human biological and cultural variation—for instance, that many cultures at most points in time have simply not experienced the pleasure of admiring blond women (so this clearly can’t be a human universal), nor that there is any sensible reason to think that being blond is a proxy for being young and fecund. (The more likely biological explanation for why “gentlemen prefer blondes”—if any is actually needed—is that a number of animal species tend to prefer unusual-looking mates, as long as they are healthy, since this increases the chances of a higher genetic diversity in their offspring.) As for the prevalence of suicide bombers among Muslims, which Miller and Kanazawa attribute to tolerance for the practice of polygyny (which leaves some men without access to a mate), they completely discard two obvious facts: First—as they acknowledge apparently without taking in the consequences—there are plenty of other polygynous cultures in the world that don’t engage in suicide bombings. Second, suicide bombing is a very recent cultural development, unknown until a few decades ago, and therefore hard to trace to any deeply engrained biological tendency.
So much for evolutionary psychology, but are there more sensible ways of thinking about human nature that are informed by reasonable philosophical insights and reliable scientific evidence? Indeed there are. Philosophically speaking, an interesting take was proposed by David Hume in his aptly titled Treatise of Human Nature, published in 1739–1740. Hume got involved in a dispute that was going on at the time between two different schools of “originalism,” the idea that human nature is what it is and does not change over time. One school, represented by Francis Hutcheson and Anthony Ashley Cooper, maintained that human beings are naturally benevolent and that this accounts for our sociability. The other school, championed by Bernard Mandeville, defended the position that human sociability arises out of self-interest. Hume, very sensibly, struck a middle ground, but in an ingenious way that foreshadowed the recent findings of the best twenty-first century science.
As pointed out by Michael Gill in his insightful analysis of the Scottish philosopher’s writings, Hume’s idea was that human nature has an “original root” (today we would say a “biological basis”) that is in fact largely concerned with self-interest and that provided for a minimal sociability early on in our history. But “society” (we would say “culture”) builds on this foundation, expanding the reach of our genuine feelings of concern from our immediate kin and neighbors to the ampler and more abstract circle of humanity at large. As Hume puts it: “Thus self-interest is the original motive to the establishment of justice; but a sympathy with public interest is the source of the moral approbation which attends that virtue.” This amounts to a dynamic (and intrinsically hopeful!) view of human nature, one that in a sense echoes Aristotle’s virtue ethics (Chapter 5) and his contention that virtue is a matter of practice. If that were not the case, everything you’ve read so far in this book would be of academic interest, but it wouldn’t help you in pursuing a eudaimonic life.
What about science? In 1953 James Watson and Francis Crick published a paper in Nature magazine entitled “A Structure for Deoxyribose Nucleic Acid.” It detailed their discovery of the structure of DNA, the hereditary molecule used by most living organisms on our planet (some use a different but similar one, called RNA). It was also the beginning of the so-called molecular revolution, a period of intense discoveries about the chemical basis of life. The revolution arguably culminated in 2003, with the publication of a complete draft of the human genome project. The project, which had started in 1989 and had cost about $3 billion, was heralded as the point at which science would finally uncover human nature, when we would be able to literally read on a CD how to make a human being—which of course immediately carried the prospect of curing all sorts of diseases, from cancer to aging itself.
By the end of the first decade of the twenty-first century, most scientists had become a bit more sober about this, humbled not just by the enormous complexity of the human genome itself but by the increasing realization of what should have been obvious from the beginning: it’s not all in our genes, far from it. Don’t get me wrong: biology, and genetics in particular, is fundamental to understanding who we are. We have large brains because of genes that make ‘em so, and that in turn is the result of evolutionary processes (though, remarkably, we still have pretty fuzzy ideas about exactly why evolution favored such a ridiculously expensive device, metabolically speaking, as the human brain). But it is increasingly clear that what has mattered most for human evolution and the shaping of human nature during the past tens of thousands of years wasn’t genes, but culture (as well as how the two interact, the so-called gene-culture coevolution).
Still, once both the human and chimp genome projects were completed, biologists thought we were very close to getting our hands on the biological basis of human nature: just compare the two sets of genomes and identify the differences. Since chimps are our closest evolutionary cousins still alive today (though separated from us by a whopping four million years of evolution), we should be able to pinpoint the genes that make us human. Again, not so fast, as it turns out. Researchers have found a surprisingly small number of proteins that appear to have undergone rapid evolution since the separation from our chimplike ancestors. One of the exceptions is a protein called FOXP2, which is involved in human speech. Some differences in regulatory sequences, like a small RNA molecule called HAR1, have also been found, though all we know about it is that it is expressed in fetal brain cells—we have no idea what it actually does.
More remarkably, the clearest burst of genetic change marking human evolution happened much, much more recently than the time of our splitting from the lineage that led to chimpanzees: between only 30,000 and 100,000 years ago. That’s puny in evolutionary terms, and clearly within a period when cultural evolution was highly relevant. (Thirty thousand years ago corresponds roughly with the evolution of language, and 100,000 years ago with the invention of agriculture.) This is a major reason why an increasing number of scientists think that human nature has been shaped by culture, acting via a feedback loop on our genetics. The obvious example is the repeated evolution of genes that produce proteins allowing human beings to metabolize lactose, which is found in milk and sugar. Not at all coincidentally, these mutations were favored in populations that had started to raise cattle—a crystal-clear example of culture guiding genetics. Hume would have been pleased.
Indeed, much of what we have learned about what makes our lives meaningful and ourselves happy does not come from molecular or evolutionary biology, but from the social sciences, particularly psychology and sociology. Modern psychology makes the same distinction that Aristotle made between happiness as the simple pursuit of pleasure and happiness as a fulsome, eudaimonic life. The empirical results are clear and would not have surprised the Greek philosopher a bit: seeking pleasure for pleasure’s sake (what psychologists call the “hedonic treadmill”) doesn’t lead us anywhere because as soon as one pleasure is achieved another one appears over the horizon. The quest never ends and—more importantly—never truly satisfies. Of course, that hasn’t stopped modern American society from essentially turning into a gigantic hedonic treadmill powered by advertising and fueling corporate profits. But perhaps that is one major reason why so many people in this country find life unsatisfactory and turn to mood-altering drugs (which are heavily advertised and produce large corporate profits). Psychologists have found that what really satisfies people instead is lifelong happiness—which comes only through the search for meaning.
Modern science has also found that our emotions can be worked out as if they were muscles, in a fashion not very dissimilar from Aristotle’s contention that virtue is a matter of practice. There are quite simple ways of doing this, including taking some time at the end of the day to mentally go through the good things you have accomplished (it worked for Julius Caesar apparently!) or to pay “gratitude visits,” that is, to take the time to thank (not necessarily in person, given our electronic age) people who have influenced you positively or have otherwise done good things for you. “Mindfulness” is another way to find meaning in life, and it can be practiced in a variety of ways, from meditation practices to the exercise of paying attention to what you do and reflecting on why you do it (in other words, doing philosophy). All of this, by the way, will result in living not only a happier life (as if that were already not enough!) but also a longer one: researchers have found that people who train themselves to engage with positive emotions live about ten years longer than those who dwell on negative ones. That’s the same order of difference that we find in life expectancy between smokers and nonsmokers (which does not at all mean that I am advising you to take up smoking as long as you think positively about it!).
Sociologists have gotten into “happiness research” too, of late, and one wonders exactly why it took the social sciences so long to figure out that it might be interesting—and useful—to see what makes people’s lives better and more meaningful. Some of the results are not at all surprising, but others will give you something unexpected to ponder. The first thing that may come as a surprise to many Americans, though it has actually been known for a while, is that there is little relationship between wealth and happiness, with some important caveats. At a societal level, for instance, the gross domestic product (GDP) of the United States steadily increased from 1978 to 2008 (to be precise, it went from $2.3 trillion to $14.4 trillion), and yet measures of self-reported happiness stayed about the same or even declined during the same period. That’s why in recent years the United Nations has started to produce statistics on what it calls the “human development index,” a more comprehensive measure that includes data not just on GDP but also on health and education.
This is not to say that “money can’t buy you happiness,” however, just that (a certain amount of) money by itself is necessary but not sufficient for happiness. Research worldwide has confirmed that we do need a minimum level of income and amenities (such as a house and basic health care) in order to be happy, but that beyond that minimum the amount of our wealth quickly becomes a poor statistical predictor of our happiness. (If you guessed that I’m now going to say, “Aristotle said so,” you are correct: the philosopher made clear that, contrary to what the Stoics were saying around his time, one does need some basic comforts in life in order to pursue eudaimonia, so that happiness is, to some extent, also a matter of luck and circumstance.)
Interestingly, researchers in the United States have been able to quantify the effect of extra income on self-reported happiness, and the results are amusing, to say the least. It turns out, for instance, that every extra $1,000 corresponds roughly to an increase of 0.002 on a social science index of happiness. To put this in context, it means that if you make an extra $100,000, your happiness will increase by about the same quantity that separates married (happier) from unmarried (unhappier) people, or employed (happier) from unemployed (unhappier) ones. I doubt, however, that the increase is linear, or indeed can even be sustained—I wouldn’t expect someone who makes, say, over a million a year to be that much happier if he manages to add another $100,000 to his bank account. And of course one has to discount these findings to some extent because wealthier people may feel somewhat obliged to report being happier, especially if being wealthy is an important part of their ethos and self-image (which I would bet it often is).
Recent surveys on happiness in the United States are illuminating in terms of what researchers call the “statistical structure of subjective well-being,” that is, the factors that seem to influence our happiness. Take the following examples with the mandatory grain of salt that correlation does not necessarily imply causation (though the two are highly correlated): women tend to be happier than men; predictably, wealthier, healthier, and more educated people are happier; married people are happier than unmarried ones; and whites are happier than any other ethnic group (again, in the United States). Exercising and eating fruit is associated with happiness, while being fat has a negative relation with subjective well-being. Oh, and having children in your household, though undoubtedly adding meaning to your life, has a surprisingly negative effect on your happiness. Moreover, remember that nonsense about women being from Venus and men from Mars? Well, actual research shows that men’s and women’s happiness seems to be affected pretty much by the same factors, in pretty much the same way. It appears that we are from the same planet after all.
What happens when we compare subjective well-being across the world? It turns out that the happiest nations are Ireland, Switzerland, Mexico, the United States, Great Britain, New Zealand, Denmark, Sweden, Finland, Norway, Luxembourg, and the Netherlands. (Notice the disproportionate number of European countries, particularly Scandinavian ones.) The unhappiest places in the world include Russia, Bulgaria, Latvia, Croatia, Hungary, and Macedonia (all in, essentially, eastern Europe). What is most interesting, however, is to find out what the happiest places have in common in terms of indicators of individual happiness. Again, the list is not entirely surprising, but here it is: low unemployment and inflation, low inequality, strong welfare states, high public spending, low pollution, high levels of democratic participation, and strong networks of friends. In other words, people are happiest in precisely the countries that best approximate John Rawls’s just state (Chapter 15).
One of the results from these studies that I find most intriguing is that age and life satisfaction are related in a complex manner best described by a U-shaped function. In the United States, you are likely to be most unhappy around age forty, though in Europe the same curve bottoms out around age fifty-four. Hence the legendary “midlife crisis” that so many people go through (particularly men, who, remember, tend to be less happy than women—other things being equal). What is stunning here is that life satisfaction then keeps climbing all the way into one’s late eighties, if one is lucky enough to live that long. I realize that you might be getting a bit tired of hearing about Aristotle, but he did say that eudaimonia is a lifelong project, the outcome of which can be determined only after one dies.
Which brings me to the last topic of our exploration of meaning and life: the relationship between age and wisdom. Wisdom, these days, is a rather old-fashioned term, though of course achieving it was the whole point of both Western and Eastern ancient philosophies (whether people called it “eudaimonia” or “enlightenment”). Wisdom cannot be equated with factual knowledge, and certainly not with technical knowledge in any particular area of application. Indeed, many older people, especially in these days of fast scientific and technological advancement, commonly know much less about a number of domains than bright young kids do. But nobody would think it likely that a seventeen-year-old computer whiz is wiser than someone who has lived on this planet for a number of decades. That’s because wisdom has to do with experiential knowledge of human social situations, a type of knowledge that can only come, well, with experience. And a major running theme throughout this book has been that coupling that experience with philosophical reflection on its meaning, as well as with the best information that modern science is capable of providing, amounts to the most powerful way to navigate our existence in an intelligent fashion.
Columbia University’s Vivian Clayton has done a lot of research on wisdom, beginning back in the 1970s, when she was perhaps the first researcher to suggest that the topic was amenable to scientific investigation. According to her, wisdom can be thought of as having three underlying components: the acquisition of knowledge (a cognitive function), the analysis of that knowledge (a reflective function), and the filtering of that knowledge through the emotions (an affective function). In other words, in order to be wise one needs to know things, to think about them, and to calibrate that knowledge through one’s emotional responses.
Subsequent research has shown that older and wiser (the two are not automatically correlated!) people tend to learn from their negative experiences and that they are capable of distinguishing situations when it makes sense to take some kind of action from situations that simply need to be accepted because there are no viable alternatives. They focus better than younger and less wise individuals on goals that are emotionally meaningful, and neurologically speaking they exercise control over their amygdala (the brain center of emotional response), using their prefrontal cortex (the brain’s executive function); they end up spending more time on positive emotions and avoiding negative ones. Philosopher and psychologist William James was probably getting at something like this when he said, “The art of being wise is the art of knowing what to overlook.”
SO WE COME TO THE END OF A JOURNEY DURING WHICH WE have used the best of what science and philosophy have been able to tell us so far about how the world works and how to find our place in it. Along the way we have seen that there are probably no gods, and that even if there are, they can’t tell us how to be moral, nor can they give meaning to our lives. We have seen that love and friendship are biologically grounded, crucial for our existence, and a constant source of philosophical challenges. We have discussed the evolutionary basis and the neurobiological underpinnings of morality, neither of which excuses us from thinking hard about what the right things to do are for us as individuals, as well as what kind of society we want and why. We have learned that willpower, and indeed our very ability to take conscious charge of our lives—the awareness on which philosophical reflection is founded—are much more limited than previously thought. And we have seen that even science itself is subject to constraints about knowledge and certainty.
The latter two points in particular raise a potentially serious objection to the whole idea of sci-phi. On the one hand, we have the undeniable fact that scientific knowledge is always provisional, which implies that some, perhaps even most, of the specific scientific claims you have read about in this book may be out of date in a year, or a decade. On the other hand, we have seen that philosophers disagree on what to think about the sort of questions we have been considering, which means that there is no established philosophical truth we can use as a bedrock for our reflections on life’s meaning. Compare this double source of uncertainty with the apparent stability of religious or mystical teachings over a span of centuries or millennia. When I was living in Knoxville, Tennessee, a local preacher was very upset about my writings and lectures about evolution and wrote an angry letter to the editor of the local paper. In the letter, the frustrated preacher wondered out loud about why some people prefer the constant uncertainties of a science that keeps changing to the bedrock certainties contained in the Bible. Good question, and we need to address it.
To begin with, of course, the Bible—like any other religious text—needs to be interpreted, and the interpretation demonstrably changes with the cultural milieu. Contrary to the stated belief of some religious fundamentalists, there is no such thing as a literal reading of scriptures, as shown by the perennial disagreement among religious sects over what particular scriptural passages actually mean. Moreover, there are plenty of teachings in the Bible—for instance, the injunction to kill children who disrespect their parents (found, among other places, in both Exodus 21:17 and Matthew 15:4)—that are in plain sight for anyone to read about, but that most people simply ignore as a vestige of a more barbarous time.
We also need to consider that there is no rational reason to accept the authority of any religious text at all. Not only can gods not possibly be the ultimate source of morality; not only is there very good reason for any rational person to doubt the existence of the supernatural to begin with; but more importantly, any such authority would have to be mediated by human agents (priests, preachers, rabbis, imams, gurus, and the like), and such mediation seems to be hopelessly subjective and open to far more doubts than the reasonings of philosophers or the tentative conclusions of scientists. At least one can argue with the former on the basis of logic and question the latter on the grounds of empirical evidence.
But there is a more fundamental reason why sci-phi’s tentativeness is not fatal: far from being a problem with that approach, it is in fact its primary virtue. We need to wrap our minds around the fact that as human beings we are inherently limited in our ability to reason and to discover things about the world. These limitations do not give us a license to arbitrarily “go beyond” reason and evidence into religion or mysticism. On the contrary, they are reminders that nobody has final answers and that the quest is open to all people who are willing to use their brain intelligently. Our limitations also give us a reason to cut ourselves a bit of slack for not getting life exactly right, for failing here and there, as humans are bound to do. This is why the eudaimonic life is always an imperfect and incomplete project, all the way until the moment of our death. But it is by far the most important of our projects, and one for which sci-phi is far better equipped to help us along the way than simple common sense, political ideology, or religious mysticism. We are social and (somewhat) rational animals, and we can reflect on how to employ our rationality to improve our lives and our societies. Seems like the meaningful thing to do.