It’s been said before, but it’s certainly worth saying again. Not only does the free market lead to material wealth, but it reduces violence.

On a recent episode of the podcast “Question of the Day,” co-host Stephen Dubner reads a question from a listener: Why haven’t humans evolved as a species away from aggression? Dubner and James Altucher deal with the question in a rather roundabout way. Altucher points out that, really, aggression has dropped for as long as we’ve recorded the data. Specifically, the percentage of violent deaths keeps declining. “As a species, we have been evolving passed aggression and I think a lot of that has to do with trade,” He says. “All these methods of trade have actually limited aggression because I no longer need to invade your country to get your resources. We can trade resources instead. And then it benefits us to be nice to each other.”

Dubner discusses a chart in his book Freakonomics (2009) that shows a decline in violent deaths: In 13th Century England, the estimated homicide rate was 23/100,000 dropping to .9/100,000 in the latter half of the 20th century. He also references Steven Pinker’s 2011 book The Better Angels of Our Nature: Why Violence Has Declined which argues that despite the contemporary world looking like a dangerous place, paratively–safer. “Violence has been in decline for thousands of years,” Pinker says in a WSJ op/ed. “and today we may be living in the most peaceable era in the existence of our species.”

Yay capitalism!

Of course, this also presents a new question: Why do people perceive that there’s more aggression now? Dubner and Altucher also address in the episode.

Listen to their podcast via Soundcloud below. They start talking about “aggression” at 1:38.