Has 2015 been a good year, or a bad one? Should we be depressed about the state of our country and the world, or hopeful and optimistic?

If you follow the headlines, things seem pretty bad. A mediocre economy. Terror attacks in Paris and California. Syria. Black men killed by police. Colleges roiled by protest. And the American polity remains divided against itself and seemingly incapable of any coherent action, either at home or overseas.

These are all real problems, but if we take the longer view, we can see that 2015 has been a pretty good year overall, and there are reasons to expect that the future will be better still.

Remember that news coverage focuses on events that journalists regard as newsworthy. No one wants to read about things that turn out as expected, and we generally expect things to go well. That’s why there will always be a story about the one fatal car crash that happens on a given day, but no story about the millions of people who travel every day in speed, safety and comfort.

Focusing on all the things that go wrong is a useful way of identifying the things we need to improve, but it prevents us from seeing how much progress we have actually made.

To get a better perspective on how we’re actually doing, we should compare the world of today, not to the perfect world we wish it would be, but to the world as it actually was in the past. When we do that, we find that things are pretty good indeed. The world of today is actually far less violent, and much wealthier than ever before.

In an important book, “The Better Angels of our Nature,” Harvard psychology professor Steven Pinker has extensively documented the almost unbelievably impressive progress our species has made toward eradicating violence. His case is hard to believe, because we see the violence still occurring and we cannot see equally vividly how much worse things used to be.

The evidence of progress, however, is overwhelming. Pinker’s data shows that our prehistoric ancestors lived almost incredibly violent lives. Life in the earliest settled states was substantially safer, but still vastly more brutal than anything we can imagine. For the more recent centuries of European and American history for which we have more direct evidence, we see sharp and ongoing declines in murder rates.

In the United States specifically, FBI data reveal that violent crime is at historic lows and has declined by more than a third since as recently as 1995.

Is war perhaps an exception to Pinker’s trend? Looking at the tens of millions of civilians and combatants who died in World War II, it is easy to suppose that the 20th century must have been the most violent in human history.

In fact, however, the rate of deaths in war also has declined sharply over time. Although the aggregate numbers killed in the two world wars are shockingly large, they represent a small fraction of the global population at the time. To be sure, not every year has been more peaceful than the one before. But even with the violence of the Syrian civil war, far fewer people are dying now in war than in the 1970s and 1980s.

According to data released by the World Bank this month, less than 10 percent of the world’s population lives in extreme poverty today — as compared with almost 40 percent just 25 years ago. That decrease in percentage is not just the result of global population growth: Almost 2 billion people lived in poverty in 1990; today, the comparable figure is a little more than 700 million.

Progress at ending poverty has been fastest in China, which embraced free-market reforms in the late 1980s, but progress has been almost as good in India, which has more recently embraced similar reforms. And even sub-Saharan Africa, where poverty actually increased slightly between 1990 and 2000, has now seen strong economic improvements.

That is all very good news, and if we looked at improvements in medicine, in science and technology, communications and transportation, we would see still more dramatic evidence that the conditions of human life are unprecedentedly good — and improving.

This is not an argument for complacency: Things get better only because people work to make them so. But it is an argument for optimism and hope.

2015 was, historically speaking, a pretty good year. And there’s good reason to expect that we’ll succeed in making 2016 better still.

Joseph R. Reisert is associate professor of American constitutional law and chairman of the department of government at Colby College in Waterville.