If you followed the news this week, you heard about riots and protests, the killing of a dictator, the suicide of a bullied teenager, and a child ignored by passersby after being struck by a car. A litany of violence and tragedy, in other words. Much like every other week.

What you probably did not hear about was a World Health Organization report which shows that a major decline in the rate of deaths caused by malaria over the past decade saved the lives of an estimated 1.1 million people. Most were young children. That's 300 people a day, every day, for a decade.

That's good news. Spectacular news, even. But the report got far less attention than any of those other stories. Not even the coincidental announcement of a malaria vaccine managed to drag it up from the ranks of forgettable filler.

What's the explanation? Maybe we don't care because the lives saved are those of foreigners far away. But that story about the child came from Foshan, a Chinese city few of us have heard of. Yet plenty were moved to tears by the video images of a toddler writhing in pain while passersby did nothing.

Another standard explanation is "media sensationalism." Journalists and editors want to grow the audience and make money so they go big on violence and tragedy - while waving off a wonderful story about more than a million lives saved.

I've never met anyone who has worked in a newsroom who thinks the reality is that simple, but let's say it is. It doesn't tell us much.

In fact, it only shifts the question slightly: If the media push tragedy and ignore triumph in order to get people's attention, why does it work? Why are people drawn to tragedy and not triumph?

I wrote about this at length in my book Risk but it mostly comes down to basic psychology.

Heaps of research show people have a "negativity bias." People shown pictures of two faces, one smiling and the other frowning, look at the frowning face first and remember it better. Negative words ("sadistic") grab attention faster than positive words ("honest").

Criticisms outweigh compliments.

Evolutionary psychologists suggest "negativity bias" is rooted in how our ancestors responded to information: Good news ("I see no lions") was nice but not urgent whereas bad news ("lion!") demanded immediate attention. Whatever its origins, its pervasiveness is clear. "Good news" may be an oxymoron in the media but that reflects human nature more than greed.

And that's just one factor at work. Another is our profound attraction to emotional stories about individual people, and its flip side - our trouble with numbers.

We understand stories not only intellectually but intuitively. We feel them. They move us. But we can only understand numbers intellectually, and with effort, and they cannot fan the embers of our emotions. This is why, as Stalin supposedly said, "one death is a tragedy but a million is a statistic."

This fundamental human paradigm - good with stories, bad with numbers - is why top-quality journalists routinely translate numbers into stories: They take the statistic, find a representative person, and tell his story.

But notice that this technique doesn't work equally well with positive and negative statistics.

If the malaria fatality rate is rising, the journalist simply has to find a child dying of malaria and tell the reader what she sees. The result will be a surge of emotion and a story that will feel urgent and powerful. But what if the malaria fatality rate is falling? How do you tell the emotionally gripping story of a child who is healthy? She eats breakfast. She goes to school. It's all perfectly ordinary and dull. There's no emotion. And no story.

In this way, the bias toward bad news deepens further. And we get to the point where the death of a single toddler in China can grab worldwide attention while a story about 300 children a day saved from death is all but ignored.

It will shock no one if I say the news is not a complete and accurate reflection of reality. We all know that. Or so we say.

The next time you hear someone bemoaning the state of the world for some reason, ask them why they think that's true. There's a good chance they will cite stories from the news - as if the news is a complete and accurate reflection of reality.

It's not. Happily for us all. There's plenty of tragedy in the world and lots of trends going in the wrong direction. But every day, people are making slow, incremental, positive improvements. Nothing dramatic. But over time, gradually, they add up. And change everything.

That's the story of much of the past two centuries. Slow, incremental economic growth made us the wealthiest people in history. Slow, incremental improvements in public health and nutrition made us the longest-lived people in history.

There's nothing inevitable about any of this. The fight against malaria made huge advances in the mid-20th century but then stalled for three decades, and even lost ground in some regions. But the progress has resumed. And more than a million people are alive as a result.

It's all wonderful, inspiring, and world-changing. Just don't expect to read about it in the news.

Correction: In my last column, I said Canada's Criminal Code, created in 1892, has never been thoroughly reviewed and revised. In fact, it was. In 1948. A spring cleaning is long overdue.