As an adolescent, I was sometimes so glum that my mom called me Eeyore. I wallowed in The Waste Land, 1984, Brave New World and other gloomy classics. Movies about nuclear annihilation--Dr. Strangelove, On the Beach--had a pornographic appeal.

On this blog, I still grouse about, well, lots of things. The downside of medical testing and the limitations of psychiatric drugs. Hype in behavioral genetics, theoretical physics, nutrition. The hawkishness of the Obama administration, which some of us naively thought would be more enlightened than its precursor. The nasty side effects of religion, communism, even humanitarian aid. The fact that in several key areas—fusion energy, supersonic transport, space colonization—applied science is regressing.

But when it comes to the big picture, I’m Pollyanna. Fatherhood helped make me less of a sourpuss. Once my kids were born, optimism seemed like a moral duty. I’ve also come to realize that, in spite of all our missteps, we are headed in the right direction. As Thanksgiving approaches, I’d like to celebrate four happy trends.

*We’re wealthier. About one fifth of the global population, or 1.4 billion people, now scrape by on less than $1.25 a day, the U.N.’s definition of “extreme poverty.” This number is shamefully high, and yet as a percentage of total population it is extremely low compared with historical levels. For most of our evolution, the vast majority of people lived hand-to-mouth, never far from starvation. Average standards of living remained stagnant for the first millennium A.D., and rose only slightly in the following 800 years. By 1800, per capita income in Western Europe was slightly less than the average income today in Africa, the world’s poorest region. Since then, the percentage of humanity living in poverty has plummeted as a result of innovations stemming from the Industrial Revolution and all its sequelae. In the past two centuries the world’s population has grown six-fold while per-capita income has grown nine-fold, contradicting the dire forecasts of Thomas Malthus and other prophets of doom. The economist Jeffrey Sachs—from whose books The End of Poverty (Penguin, 2005) and Common Wealth (Penguin, 2008) I extracted the stats above—believes that we can eradicate extreme poverty within a generation, if we have the will to do so. I heard a similar message last week at “Feeding the World,” a meeting in New York. Agricultural experts from academia, industry, government and nonprofits contended that we have the means to feed not only the seven billion people alive today but also the nine billion expected to be alive by mid-century.

*We’re healthier. For most of human history and prehistory, people lived to be about 30 years old, on average, according to Wikipedia. Examinations of skeletons reveal that average life spans dipped a few years after the transition from the Paleolithic, when our ancestors lived as hunter-gatherers, to the Neolithic, when we started farming andsettling down into villages. But since the early 20th century, life spans have more than doubled to a global average approaching 70 years as a result of advances in the delivery and care of infants, improved treatment of water and sewage, better nutrition, vaccines, antibiotics and other medical and public-health measures. According to The World Factbook, published by the CIA, 29 countries now have a life expectancy above 80. (The U.S., which spends much more on health care per capita than any other country, is not among this elite group. Sorry, couldn’t resist.)

*We’re freer. Just as longevity and prosperity have surged in the past century, so has freedom. The nonprofit think tank Freedom House, which charts the ebbs and flows of democracy world-wide, defines a nation as democratic, or “free,” if it meets two criteria. First, it must “elect representatives who have a decisive impact on public policies and are accountable to the electorate.” Second, the nation must allow “freedoms of expression and belief, associational and organizational rights, rule of law, and personal autonomy without interference from the state.” Freedom House categorizes 87 of the world’s 194 nations as “free” and another 60 as “partly free.” People are “not free” in 47 countries, home to 34 percent of the global population. (China accounts for roughly half of this percentage.) Global freedom has declined a bit recently, but even with this backsliding more people live more freely than at any time in history. Only 12 percent of humanity lived under democratic rule in 1900 and 31 percent in 1950, according to How War Began (Texas A & M Press, 2004), by anthropologist Keith Otterbein.

*We’re more peaceful. Contrary to the implication of daily news headlines about civil wars and insurgencies, drone strikes, terrorist attacks and other acts of group violence, our era is quite peaceful by historical standards. Psychologist Steven Pinker and political scientist Joshua Goldstein have drawn attention to this counter-intuitive trend, and so do I in my forthcoming book The End of War. As Goldstein points out in Foreign Policy, war killed fewer people between 2000 and 2010 than in any decade in the previous century. Since 2000 annual combat casualties have averaged about 55,000—or 250,000 if you count civilians killed by war-related disease, famine and exposure. According to an analysis by the political scientist Milton Leitenberg, war killed almost 4 million people per year during the cataclysmic first half of the 20th century and almost a million a year during the second half. Keep in mind that during this same period, the global population quadrupled.

So there you have it. Things are getting better, folks! Yes, we still face huge problems: upward-creeping temperatures and populations, environmental degradation and economic inequality, terrorism and militarism, AIDS and other plagues, [add your own favorite problems here]. But given how far we’ve come toward creating a healthier, wealthier, freer and more peaceful world, surely we can go much further. That’s what I’ll give thanks for as I chow down my turkey.