MR. KOJO NNAMDIFrom WAMU 88.5 at American University in Washington, welcome to "The Kojo Nnamdi Show," connecting your neighborhood with the world. Not everyone keeps a brain in a jar on his or her desk. And even among the scientists who might, most don't have fans so enthusiastic that an action figure of them has been proposed. But Steven Pinker isn't just any scientist. He's made topics, ranging from the roots of language to the human genome, interesting to the nonscientists among us.

MR. KOJO NNAMDINow he's found that violence, reports of which are so pervasive, it seems to be at an all-time high, is actually on the decline. In fact, we may be living in the most peaceful era in human history. Steven Pinker joins us in studio. He's a cognitive scientist and professor of psychology at Harvard University. His latest book is "The Better Angels of our Nature: Why Violence Has Declined." Steven Pinker, thank you so much for joining us.

MR. STEVEN PINKEROh, thank you.

NNAMDIEvery time we turn on the news, pick up the newspaper or, depending on our neighborhood, walk down the street, we seem to see examples of violence in our society. But you say we're actually living in what is probably the most peaceful era ever. If a time machine were to magically appear in this studio right now, where would I really not want to go?

PINKERThe past...

NNAMDIGood answer.

PINKER...particularly. Well, it depends on where because rates of violence do fluctuate. They haven't gone smoothly downhill from a period of original violence. But by many measures, today is an unusually peaceable time. You could be mislead if you just look at the number of violent events that are on the news 'cause that's what the news does. They -- wherever the violence occurs, you can bet they'll find it. But what they don't cover is the many more people who die peacefully in their sleep. It's not news if Vladimir in Lithuania dies of a heart attack. It is if he gets blown up.

NNAMDIHow good are things now compared to, well, the bad old days?

PINKERWell, let's say the -- if you can make the comparison to tribal ways of life when our species spent most of its existence hunting and gathering without any police force or government or court system, there, the rate of violent death was about 15 percent, in many societies as high as 60 percent. Even in the 20th Century -- you throw in all the world wars, all the genocides, all the famines -- it's no more than 3 percent. And, of course, those deaths were all bunched up in the middle decades. For the last 60 years in Europe and the last 20 years in Asia, it's been far more peaceful than that.

NNAMDISo if violence is on the decline and the FBI reports crime is down across the U.S., why do we continue to think it's so prevalent?

PINKERPartly, it's a quirk of the human mind. We're not intuitive statisticians. We couldn't be. We don't have access to the FBI figures unless we're real data nerds. What we do is we think of examples. We remember someone getting shot or blown up or incinerated, and our impression of the risk depends on our ability to remember gory examples. It's only when you look at the denominator of the fraction -- that is the total number of people on the planet who could be killed violently, but, in fact, aren't -- that you appreciate how much violence has come down.

NNAMDIIf you'd like to join the conversation, call us at 800-433-8850. We're talking with Steven Pinker. He's a cognitive scientist and professor of psychology at Harvard University. His latest book is called "The Better Angels of our Nature: Why Violence Has Declined." Are you seeing signs that violence is on the decline, or do you have evidence to the contrary? And what do you attribute it to? 800-433-8850. You can send email to us at kojo@wamu.org, or you can join us by sending us a tweet, @kojoshow, or email to -- or you can go to our website kojoshow.org. Join the conversation there.

NNAMDIWe're always coming up with a number of our own hypotheses for why things are, well, getting worse. And even though media and technology expose us to seemingly endless accounts and images of violence, you say that our correlations that so many of us made between, say, video games and crime are nonsense, bunk. Why?

PINKERYes. Well, video games have skyrocketed in popularity since the 1990s. They're now as popular as movies, television, other kinds of entertainment, and they sure are violent. There's just no question about that. But it's been since the 1990s that American crime rates have plunged. The homicide rate now is much less than half of what it was at its peak in the late 1980s. So they've gone in opposite directions.

PINKERAnd people often forget how much violent entertainment there has been in the past. You look at Shakespeare's tragedies. You look at "Homer," "The Iliad and the Odyssey." You look at "The Lives of the Saints" that were tortured to death in gruesome ways. You look at the Old Testament with all the genocides. You look at Chaucer. You look at Beowulf. It's just all one big bloody mess. People love to consume simulated violence. The difference now is that they've lost a lot of their taste for real-life violence.

NNAMDIWe blamed comic books in the 1950s...

PINKERExactly, that's right. It was comic books then.

NNAMDI...for juvenile delinquency.

PINKERThat was the moral panic. Exactly.

NNAMDIEven though that was at a time when violence among young people was actually in the decline.

PINKERThat's right. The lowest -- the safest period in American history was in the 1950s. And then, for reasons that no one completely understands, the violent crime rate shot up in the 1960s, stayed high in the '70s and '80s, but starting in the '90s fell back to earth.

NNAMDIGetting back to the video games, you do not join the chorus of people who thinks that technology is turning our brains to mush.

PINKERNo, that's right.

NNAMDIWhy not?

PINKERWell, the -- for one thing, technology augments the powers of the mind enormously. You've probably been at a dinner when someone makes a claim and someone else pulls out a smartphone and immediately fact-checks it.

PINKERAnd it's a sobering experience to realize how many of our beliefs are nonsense, how poor human memory is at keeping track of facts. I remember in school having to learn how to calculate square roots with paper and pencil.

NNAMDIMm hmm.

PINKERPerhaps you were taught that as well.

NNAMDIYes.

PINKERAnd it is tedious. Kids aren't taught that anymore, and they are missing nothing. It was just a waste of human brain power. The more we can outsource intelligence to machines and reserve it for reasoning and deduction, the better off we are.

NNAMDIEven as we become somewhat desensitized to reports of shootings, stabbings and war in the news, we blanch at the cruelties humans inflict upon humans in centuries past. Were peoples' sensibilities offended by torture and brutalities inflicted in past centuries, or have we become more sensitive?

PINKERWe've definitely become more sensitive. One can -- it's often shocking to see how insouciant people used to be about absolutely gruesome violence. My favorite example is an entry from the diary of the famous writer Samuel Pepys where it is -- one entry is, well, I went out to Charring Cross Square to see Maj. Hastings drawn and quartered. He looked about as cheerful as any man could do in that situation. Then I went to the Tavern for some oysters with some buddies.

PINKERNow, being drawn and quartered means being partly strangled, then, while still alive, being castrated, then being disemboweled and having your organs shown burned before your eyes, finally, being decapitated -- something that would be beyond the imagination of even consumers of splatter films nowadays. But then it merited just a mention in a diary followed by what he had for lunch.

NNAMDIAnd today we would think that inconceivable.

PINKERToday, yeah, we're much more sensitive. It's interesting to see new categories of violence that we are increasingly concerned over. A couple examples are the recent concern about bullying. The president of the United States gave a talk about -- a speech on stamping out bullying. Twenty years ago, it was boys will be boys. It's part of childhood. Everyone needs to get a little toughened up. Now, it's a heinous category of personal violence.

PINKEROr even the opposition to capital punishment in this country. We're one of the few developed democracies that still has capital punishment, even then, only in about two-thirds of the states. And even then, it's applied to a tiny, tiny fraction of our homicides. There are about 50 executions a year in this country out of 17,000 murders. And you'll have nuns holding candles for a vigil for some vicious serial killer in Texas. And, granted, maybe they should hold the candles and protest it. But 100 years ago, they would've been seen as sentimental wimps.

PINKERPeople were hanged for horse theft and counterfeiting and so on. But the opposition to capital punishment is another example of how our sensibilities have become increasingly fine-tuned.

NNAMDIAgain, the number to call, 800-433-8850. Please don your headsets. We'll be talking with Gary in Washington, D.C. Gary, you're on the air. Go ahead, please.

GARYGood afternoon, guys. Two quick things, one, I think the author hasn't mentioned that the threat of violence has significantly increased over the years, particularly with nuclear weapons. It would only take one small nuclear war among Pakistan, India and China to wipe out at least half of the population. The other thing is a lot of people would say that if you take into account the violence against animals that occur through our food system, that violence is still on the increase throughout the world. I'm not one of those persons, but a lot of people would say that.

NNAMDIHere's Steven Pinker.

PINKERWell, it's certainly true that our capacity for violence has increased, thanks to nuclear weapons, though one could see that two ways. If you look at how much violence has perpetrated as a proportion of how much could be perpetrated given the technology available, then we're really at an all-time low. I do discuss nuclear weapons in "Better Angels." And nuclear weapons have fallen into a special category that's almost irrelevant to the conduct of actual wars.

PINKERThey've become almost more of a status symbol for some developing countries and a -- something for the Dr. Strangeloves to speculate about as to how they'd be deployed in an all-out Armageddon. But they've actually had very little impact on the waging of wars, as we see in the fact that many non-nuclear nations have challenged nuclear ones, secure in the knowledge that nuclear weapons have become so taboo as a category of weapon that their use is pretty much unthinkable, except for these doomsday scenarios.

NNAMDIDo you give any credence to the idea that nuclear weapons have helped to hinder violence? Some people argue that the creators of the nuclear bomb deserve the Nobel Peace Prize.

PINKERI don't, following the arguments from several political scientists. One of them being that they -- that the damage they do is so disproportionate to any military strategic or tactical aim, that they're pretty much off the table as a live option, and that that repugnance has spread even to the smaller tactical nuclear weapons, which have not been deployed, because nuclear weapons, psychologically, are in this special unthinkable category.

PINKERAlso, the second World War proved that conventional weapons could do so much damage that you really don't want to get into another world war between the super powers, even if all they had were old-fashioned tanks and artillery and bombers. The amount of damage that they could do was -- maybe it's thinkable, but it was still horrendous enough that the U.S. and the U.S.S.R. stayed out of each other's faces as much as they could during the Cold War.

NNAMDIWhile saying that he was not speaking on his own behalf, our caller made a reference to the cruelty that some people say is inflicted on animals that we use for food. Is that yet another indication of our increasing sensitivity towards violence?

PINKERI think it is because cruel treatment of animals on farms and slaughterhouses and wheeling ships goes back centuries, perhaps, millennia. Carving animals alive or roasting them alive was a common practice. Nailing geese to the floor of a barn so that their flesh would grow more tender. All of these terrible practices go way back. It is true that probably more lives are made miserable and snuffed out over the last couple of decades because of the growing taste for chicken because it takes 200 chickens to provide the same amount of meat as one cow.

PINKERSo if people think that chicken is healthier then beef, which is a general perception, it is true that more unhappy lives are brought into being and then snuffed out than when people chow down on a good steak. But even that, I see changing -- certainly, there's an increase in vegetarianism. But probably even more significant, people are willing to support measures that enforce more humane treatment of animals in farms. They pay more for the products. They vote in plebiscites in probably half a dozen different states, and I think that's a trend that's going to grow.

NNAMDIWe're talking with Steven Pinker. His latest book is called "The Better Angels of Our Nature: Why Violence Has Declined." He's a cognitive scientist and professor of psychology at Harvard University. We're taking your calls at 800-433-8850. Are you skeptical about Steven Pinker's findings? Call in with your questions about his research, or you can send us email to kojo@wamu.org. If you have been intrigued or incensed by any of Steven Pinker's earlier works, now is your chance to call in with your questions, 800-433-8850. I'm Kojo Nnamdi.

NNAMDIWelcome back to our conversation with Steven Pinker. He's a cognitive scientist and professor of psychology at Harvard University. We're discussing his latest book, "The Better Angels of Our Nature: Why Violence Has Declined," and taking your calls at 800-433-8850. Do you think media outlets exaggerate or give too much airtime and column space to accounts of violence? 800-433-8850.

NNAMDISteven Pinker, we don't have to go back to medieval times or to extremes like you described, like drawing and quartering for examples of violence we now find taboo. I find it fascinating that you include an image of a coffee ad from 1952 in the book that most Americans, today, would find troubling, maybe even horrifying. Could you talk about that, please?

PINKERYes, it shows -- it's an ad for a brand of coffee that shows a husband with his wife over his knee, spanking her for having bought the wrong brand of coffee. It's kind of a sexy ad. She's a very attractive model. But, nowadays, that casual lighthearted treatment of domestic abuse would be unthinkable. There would be protests. It would be considered the epitome of bad taste, and people would shun the coffee in droves. There are many examples like that of popular culture from past decades that remind us of changes in standards.

PINKERTwo other examples are -- a common scene in children's entertainment where the child is naughty, and the mother says, wait till your father gets home. And then when dad gets home, he removes his belt and uses it as a weapon to beat the child with the belt and the belt buckle. Nowadays, a social worker would take the father away and imprison him for child abuse. Another example is one of the baby boomers favorite situation comedies, "The Honeymooners," with Jackie Gleason, where the recurring laugh line was, one of these days, Alice, pow, right in the kisser...

NNAMDITo the moon.

PINKER...or, pow, to the moon. In other words, I'll punch you so hard that you'll go to the moon. Again, that would be subject to instant boycotts today, but then it drew reliable laughs.

NNAMDIYou know, today, when the father takes off his belt, the child has Child and Family Services on speed dial.

NNAMDIHere is Marshall in Manassas, Va. Manassas, you're on the air. Go ahead, please.

MARSHALLHello, Kojo and hello, Professor. I think this is a very interesting topic, and thank you for taking my call. You've given some really good examples of how violence has been on the decline and how we perceive it, but the subtext of your book is why. And you haven't really touched much on that topic. Maybe you could go into that a little bit. Just evolution, is this a social development? What are your thoughts?

PINKERIndeed, it's -- I doubt that it's evolution in the biologist sense of a change in our genome. It's not impossible, but at least some of the declines have occurred too recently for it to be Darwinian natural selection. Because natural selection has a speed limit measured in generations. And some of the declines we're talking about, like domestic abuse, are just a couple of decades old. I think it has been changes in our cultural and material environment.

PINKERI think one of the causes is the consolidation of government, the fact that you can outsource your revenge to the court system and the police, so you don't have to react like the Corleones or the Sopranos. But you can dial 911 or file a lawsuit. I think that helps. I think another thing that's helped is the growth of trade and commerce and economic cooperation, more broadly. The way to get ahead nowadays is generally not to try to plunder your neighbors' farmland as it was in the Middle Ages, but to make stuff that he wants to buy and sell it to him and buy some of the stuff that he can sell you.

PINKERAnd positive-sum exchange leads to less violence than zero-sum plunder. And, I think, a third force has been the general expansion of peoples' horizons through literacy and reading, through journalism, through education, through fiction, through memoir, all ways in which we can experience what the world is like from other peoples' point of view to realize that they're human beings as well. We might think that we are special and noble and heroic and the other side is perpetually evil and vicious and perfidious.

PINKERBut when you look over history and you see, you know, empires rise, empires fall. Everyone always thinks that they're on the side of the angels. And you kind of step back, and you think, well, maybe, we're not so different from them. And maybe we'd all be better off if we sat down and figured out a way to reduce violence instead of just trying to win every contest.

NNAMDIIn the context of the notion that our violence has, in a way, been outsourced to authorities and governments, as a teenager you, it is my understanding, were an anarchist, an idea that you apparently rejected when you saw what could happen when there was a true absence of authority. Tell us about that experience. And did it inspire you to take this subject on?

PINKERI -- well, I grew up in Montreal, which is known for two things, one is that it's -- by American standards, has a very low rate of violent crime. And the other is, as a part of a French-speaking province, everyone was always going on strike.

PINKERAnd what -- one day -- and I had thought -- I was 13 years old -- I think I could be forgiven. But I had a friend whose older brother was a student radical, and he convinced me that government is -- and police were unnecessary, that if you don't force people to declare what's their property and what's someone else's property, they won't have anything to fight over. And since humans are naturally peaceful and cooperative and will naturally share, we don't need money, we don't need police, we don't need armies and so on.

PINKERWell, it sounded like a pretty good idea at the time, until the day that it was the turn of the police to go on strike. And, within a few hours, this wonderfully peaceable city was convulsed by rioting, looting, arson and two fatal shootings until they called in the Mounties to restore order.

NNAMDISo it's, what, 1969.

PINKER1969, that's right. Well, that was a kind of a sobering experience because I remember arguing with my parents over the dinner table, well, you know, no one's ever tried it. If you ever -- if we just -- I'd be proven right if the police just stayed home one day, and you'd see. Everyone would -- why would anyone engage in violence? It's so illogical. So it's a good taste of life as a scientist, namely sometimes your cherished hypotheses can be cruelly falsified by the world. And from that time on, I've not been an anarchist.

NNAMDIWell, if, on the one hand, the creation of big institutions like government has helped decrease violence and, on the other hand, there's the empathy factor that makes violence less and less acceptable through time, is the decrease in violence an individual or a collective accomplishment?

PINKERI think it's both 'cause the collectivity has to be impulses that start with some individuals and are accepted by others and that -- once a belief or a value goes viral, we call it collective, we call it cultural. But at the more microscopic level, it's just a question of individual people thinking, gee, this isn't really a very good way to do things, and other people hearing his or her case and saying, you know, you're right. That makes a lot of sense.

PINKERAnd you can see that happening in the history of various abolitions of institutionalized violence, that philosophers start out, and they write an argument why, say, strapping someone to a wagon wheel and shattering his limps with a sledge hammer is probably not the ideal form of criminal justice. And the -- their argument is published as a pamphlet. This is, say, in the 18th century. It goes viral. Everyone's arguing about it in pubs and coffee houses and salons.

PINKEREventually, it finds its way into the arguments of decision makers, and then they pass, say, in our country, the 8th Amendment to the Constitution, the ban on cruel and unusual punishment.

NNAMDISo should we see the whole argument about enhanced interrogation and waterboarding in the fight against terrorism, in that context?

PINKERYes, as a kind of -- it can't be compared to the kinds of institutionalized torture that were the norm in most countries until the 18th century. For one thing, there is a difference between using torture to extract information that could, at least in the minds of the authorities, save lives -- granted that that probably did not happen much, if at all, during the years of waterboarding. But that, as a rationale, is very different from using torture to punish someone for a crime.

PINKERSo that's one difference. Another difference is there's a huge difference between a practice that is clandestine, that's done for a couple of years. When it's exposed, it's universally condemned, and then it's abandoned, versus a custom that was in place for centuries, maybe millennia. Official, welcomed, embraced, enjoyed, people would bring out the whole family to watch prisoners struggle and scream as they were burned to death or slowly strangled or disemboweled.

PINKERSo it is true that torture, regrettably, has not been brought down to zero. But there's really no comparison between the waterboarding of the -- in 2002, 2003 and the medieval torture that went on for centuries.

NNAMDIWe're talking with Steven Pinker about his latest book, "The Better Angels of Our Nature: Why Violence Has Declined." Now, on to the telephones. Keith, in Frederick, Md., your turn.

KEITHOh, good afternoon. My question is, what size population, do you think, mandates control of life or death through the government? I mean, it's entertaining to think the state has control, the county has control, perhaps a township has control to adjudicate life and death for somebody. The extreme example would be a town of three where two decide to get rid of the other one. Is there any consensus of what size population that's required for life and death decisions?

PINKERAre you referring specifically to capital punishment?

KEITHYes.

PINKERWell, the trend in every country but the United States has been that no size government may be permitted to deliberately take a life. And the 35 or so American states that still have capital punishment on the books are very much standing in opposition to that sweeping trend. It used to be that pretty much every country had capital punishment. And they would have hundreds of crimes that they would use it for, like counterfeiting, like stealing cabbages, like criticizing the king or criticizing the king's garden -- what used to be a capital offense.

PINKERSo the trend, over the last few centuries, has been to reduce the number of capital crimes so that it's only applied for murder and high treason, to use it sparingly if it's legal, but, most of all, to outlaw it. And, again, the United States -- or the 35 states in the United States that still have it are outliers, and I expect that the trend over the next few decades will be that the number of states that have it will go down. That's been the direction of the -- in the last few years, when another two or three states have abolished capital punishment.

NNAMDIKeith, thank you so much for your call. You, too, can call us at 800-433-8850. We move on to Susan in Rockville, Md. Hi, Susan.

SUSANHi. Kojo, you -- as always, you rock, and this is a great conversation. And my question is, though -- I have a 13-year-old who we kept largely unplugged. And then the jungle drums starting beating, and, you know, he has access to some video games, but pretty -- he's a lot less plugged-in than some of his friends. However, like most 13-, 14-year-old guys, his current favorite game, when he plays, is something involving how many cars can he crash and how many cars can he steal and cause mayhem in the streets.

SUSANSo what I am hoping to hold onto is -- and I want to know if there's any research or if you've looked into this, could all of this be useful for him in sublimating angry tendencies and make him a more law-abiding citizen up the road? Not that he's not one now. And would this at all contribute to the trend that you're noticing?

PINKERYeah. I doubt that either extreme position is true, neither that -- I don't believe in the hydraulic theory of violence. Namely, there's a constant pressure to be part of violent acts and if you get it out through violent entertainment, you'll be less likely to do it in real life. But I also don't believe in the contagion theory that violent -- consuming violent entertainment makes you violent. I think that the relationship is loose, if there is one at all. In general, violent -- more violent people tend to enjoy violent entertainment more, but that, too, is a loose correlation.

PINKERSo, in general, I think that what actually happens on the streets, in the playground, is going to be much more important than what happens on the computer screen. I think there can be an influence from the news. That is, people do get a sense of how violent life is around them. But most people are pretty good at distinguishing their entertainment from real life. Otherwise you'd have people walking out of "Romeo and Juliet" and engaging in knife fights on the street or, you know, threatening their sons and daughters.

NNAMDII'd like to pursue that for a second because you seem to make the argument that we don't necessarily learn violence, that, indeed, what we might have to do is unlearn violence. Understanding the way the mind works is your domain, and you say we don't have to look much farther than the nearest toddler, that -- for evidence, that violence is behavior for which we are wired.

PINKERYes, there's -- the most violent stage of life is two. That's when almost half of toddlers kick, bite and hit, and the rate goes down from there. Probably the second most violent time is late adolescence and early adulthood, the 15- to 30-year range. So I don't think that we have to learn how to aggress. I think we do modulate the degree of aggression depending on how much we think we need it to survive in our local environment.

PINKERSo it can obviously go up or down. Otherwise I wouldn't have had a book to write because it has gone down. But I don't think that it necessarily appears or goes up because we need lessons on -- that -- or someone telling us, gee, have you heard about this great new idea? It's called violence.

PINKERI think we're actually pretty good at it, starting at the age of two.

NNAMDISo does our genetic make-up make us more or less prone to violence?

PINKERWell, I call the book "The Better Angels of Our Nature" -- I stole the phrase, of course, from Abraham Lincoln -- to convey the idea that there are many parts to the mind, something that Lincoln himself alluded to with that expression. Namely, there are parts of human nature that are rather ugly or demonic, if you want to keep the metaphor, the thirst for revenge, for dominance, the capacity for sadism, the ability just to engage in callous exploitation.

PINKEROn the other hand, we also have empathy. We have self control. We have a moral sense. We have reason and rationality. And so the question, are we basically good, basically evil, basically violent, basically peaceful, is the wrong question. We have parts of the brain that allow us to be all of those things. The interesting question is, which part of the brain prevails and actually gets to press the buttons of behavior in a given environment?

NNAMDILike most big thinkers, you are not without detractors. What do you say to people who are uncomfortable with your writings on nature versus nurture, the roots of human nature or your take on whether or not the soul exists?

PINKERYes. Well, I wrote one book specifically addressed to those concerns, a book called "The Blank Slate: The Modern Denial of Human Nature" where I examine why that the very idea there is such a thing as human nature should be so controversial. And I outline various fears that people have. Well, if you're saying that we're nothing but our brains, and our brains work by the laws of chemistry, then wouldn't that remove moral responsibility? No one would be responsible for anything they do. They would just say, well, I couldn't help it.

PINKERIt was a biochemical imbalance in my brain, or it was my genes, or it was my evolutionary history. Or maybe another fear is, if we're pre-programmed to be violent, selfish, racist, then making the world a better place is just a waste of time. People will just screw it up, no matter what you do. Or life would have no meaning and purpose if I'm just my brain. And when my brain stops working -- I no longer exist -- why don't I just kill myself right now?

PINKERSo these are the kinds of moral and emotion and political concerns that, I think, always hover over the science of the mind and brain. I consider them kind of a nuisance in actually trying to figure how the mind works, which is why I wrote this book, and I think that all of them are groundless. I think that one can have plenty of meaning and purpose in one's life. I think that one can certainly make the world a better place, even if we are our brains and our brains are products of the evolutionary process.

NNAMDIOn to Nick in Beltsville, Md. Susan, thank you for your call. Nick, you're on the air. Go ahead, please.

NICKYes. You did bring up evolution again, which I'm glad, because it pertains to my comment that I was going to make, is that I was disagreeing with what you were saying about evolution being of a more Darwinistic or, like, basically physical concept. I think that evolution is more so -- well, complimentarily something that occurs in the mind as well, like our -- as in, like, our state of mind, and it could have an impact on us in a physical sense.

NICKWe could, you know, see something like the X-Men mutations occur, which, I guess, might incline that, you know, there would be some sort of physical mutation manifestation later on, wherein that would apply that our actions and our conduct would have a physical impact on us from the inside.

NNAMDIYou're losing me, Nick. You're losing me, Nick. Do you have a question?

NICKWell, I'm wondering how you feel about that. I'd like to know what you have to say about that. Is -- should evolution be kept in the constructs and limited to a physical concept, or could we apply evolution in more of an esoteric, spiritual, invisible kind of process?

PINKERMm hmm. Well, there -- certainly, the brain, as a physical organ, is subject to the processes of evolution. And you mentioned the X-Men, and I've got to confess to not being familiar with it. But if you're referring to change -- mutations in our DNA that change the wiring or chemistry of the brain and, as a result, change our tendencies toward violence, then you're right. Those certainly can occur, and it's just another example of Darwinian natural selection. But in this case, the genes shape the brain instead of just the skin and the bones and the muscles.

PINKERAnd, in addition to that, though, sometimes people use the word evolution to refer to cultural evolution, that is, the historical changes that accumulate in any society that don't involve any changes in the brain at birth, but more in the content of the brain as we live our lives and are immersed in our cultures. And, in fact, the changes that I talk about in "Better Angels" are a form of cultural evolution. I try not to use the world cultural evolution just because it's so easy to confuse with physical Darwinian evolution.

PINKERAnd I think that most of what we call cultural evolution can just be called history. And there's just less danger of confusion in that regard. But I do discuss the two possibilities, and I put most of my explanatory bets on what you could call a cultural evolution or history.

NNAMDIThank you very much for your call, Nick. We've got to take a short break. When we come back, we'll continue this conversation with Steven Pinker. His latest book is called "The Better Angels of Our Nature: Why Violence has Declined." We still have a couple of phone lines open, so call us at 800-433-8850, or go to our website, kojoshow.org. Join the conversation there. Send us a tweet, @kojoshow, or email to kojo@wamu.org. I'm Kojo Nnamdi.

NNAMDIIt's a conversation with Steven Pinker about his latest book "The Better Angels of Our Nature: Why Violence Has Declined." Steven Pinker is a cognitive scientist and professor of psychology at Harvard University. Let's go to Victoria in Silver Spring, Md. Victoria, you're on the air. Go ahead, please.

VICTORIAHi. I have a comment. I disagree with the author. I think he's looking at violence too narrowly. I think, unfortunately, America is one of the most violent countries on Earth. Not only do we have more arms per person than any other developed nation, more importantly, our violence is mostly concentrated in our wars abroad -- ten years in Afghanistan, eight years in Iraq, hundreds of thousands of civilians killed, over 6,000 soldiers dead, and countless others with severe injuries while the expense for these wars has drained our society. Finally, we...

NNAMDIOkay. Victoria -- Victoria -- Victoria, I guess...

VICTORIAMay I say -- may I add one more point? We're targeting our enemies abroad. We're targeting them more covertly than we did in the past. In the '60s, we used to covertly, you know, kill people, and that was controversial. Today we'll send a drone to Pakistan or Afghanistan to take someone out, and these -- you know, these may be bad guys, but there's no trial going on here. There's no jury. We're just killing them overtly, and that seems to be okay.

NNAMDISo when you compare what we're doing today -- and you mentioned the 1960s -- there is no less violence as far as you are concerned than there were in the 1960s?

VICTORIAIn terms of our wars, no, there is no less violence.

NNAMDIOkay. Here is Steven Pinker.

PINKERNo. The -- well, it is true, actually, that America is more violent than other western democracies. It's certainly not true that America is the most violent country in the world by any measure, nor is it more violent now than it used to be. Quite the contrary, the war in Vietnam resulted in many more deaths, both of American soldiers -- 56,000 compared to in the neighborhood of 5,000. Far more deaths of Vietnamese, in the range of 2 to 3 million compared to probably 150,000 Iraqis.

PINKERAlso, the vast majority of the deaths in Iraq were Iraqis killing Iraqis, not Americans killing Iraqis. Now, granted, it was probably very stupid and irresponsible to plunge the country into anarchy in which the citizens could kill each other. But it isn't the same as a carpet bombing of the sort that we saw during the Vietnam War or the firebombing -- to say nothing of the nuclear attacks during World War II.

PINKERDrones are a perfect example, and one, of course, could make -- and, in fact, I agree with the argument that drones should not be used to take out American citizens without many layers of due process. But if you compare a drone with, say, carpet bombing or firebombing, which is the technique to get rid of nuisances in past wars, there's just no comparison. Drones are an enormous advance in humanitarian waging of war.

PINKERNow, perhaps the country shouldn't be in there waging war in the first place, but given that it's waging a war, the amount of collateral damage is just incomparably less than it was in wars such as Vietnam.

NNAMDIVictoria?

VICTORIAYeah. I guess I have to agree with that. He's almost saying that the level of war -- level of collateral damage and carnage that is -- because it's slightly less in terms of numbers is more acceptable. I don't think if you look at the numbers of Iraqi civilians and the number of...

NNAMDINo. No. Wait a minute. Victoria, he's not saying it's more acceptable. He's simply saying it's less.

PINKERThere are fewer of them, yeah.

VICTORIAYeah. I don't think it's a matter of just comparing sheer numbers. We're also talking about our reputation in the world. What is -- and it has...

NNAMDIOkay. For the time being, allow me to limit it to comparing sheer numbers because, Steven Pinker, it seems like we don't like the idea, or some of us don't like the idea, of a numerical decline in violence. Why is that?

PINKERPart of it is moralistic. If you want to make a prosecutorial brief against some particular demon, say, in this case, the United States, to say that, in fact, the amount of human damage has gone down kind of weakens the case for the prosecution. So there is always a -- for people who, and perhaps rightly, stand up to the victims of violence and want to demonize the perpetrators, to say that they're less demonic than they used to be seems to undercut your moral case.

PINKERThere's -- and I think there's also an unwillingness of many people to think quantitatively, to say Vietnam, Iraq, what's the difference? And I say, well, here's the difference, 58,000 American deaths versus 5,000 America deaths, 3 million Vietnamese deaths versus 150,000 Iraqi deaths. That's a big difference. If it's a difference of 90 percent, that's an awful lot of people who are alive today who would have been dead if nothing had changed in the way that the nation wages war.

NNAMDIBut it should make no difference in whether or not somebody opposes or supports the war on principle.

PINKERNo. You could argue that we shouldn't be waging those wars in the first place, a claim that I'm perfectly sympathetic to. But one also must be aware of the enormous progress that has been made and that forms of violence in the past that were considered just what countries do are now considered beyond the pale.

NNAMDIThere is the external, and then there is the internal. Victoria, thank you for you call. Here is Vivian in Washington, D.C. Vivian, you're on the air. Go ahead, please.

VIVIANYes. Thank you, Kojo, for taking my call. I'm calling because there is much violence going on that is probably not reported by the police, like the elderly being robbed, the blind being -- people being blinded by doctors intentionally, medication they're giving people that's killing them. That's a form of violence.

PINKERWell, I would distinguish medical errors, where there is no malice or desire to harm, from intentional violence, like someone sticking a dagger in someone's eyes as they used to do as a form of punishment in the Middle Ages. So just as in -- we distinguish in car accidents between a car that spins out of control and kills someone and, say, someone taking aim with their car and mowing someone down, so I wouldn't put the category of medical errors in the same category as deliberate violence.

PINKERYou're certainly right, though, to raise the issue that we can't take reports to the police as an indicator of levels of violence because it depends not just on how many crimes are committed, but how willing people are to report them to the police. That's one of the reasons that I concentrate in the book on homicides because everyone notices a dead body or a missing person, and so there's much less reporting by us in homicide than for other crimes.

PINKERWhen I do report out the crimes, instead of looking at police reports, which I agree are misleading, I use the FBI's Crime Victimization Survey, which is not foolproof, but it's much better when someone sits down with us, each person in a sample and just goes through a list of crimes and said, has any of these happened to you in the past years -- in the past year, in an anonymous safe setting.

PINKERThere, they're not reporting it to the police. They don't have to go through the whole rigmarole. They don't have to worry about their own safety, but you get a -- I think, a better measure with that technique than police reports.

NNAMDIVivian, thank you very much for your call. Here now, Clyde in Springfield, Va. Clyde, you're on the air. Go ahead, please.

CLYDEYes. I was wondering if the author had read the Washington Post review on his book this past Sunday, especially the particular comments about the riots -- Civil Rights Riots of the '60s and their causation.

PINKERYes. I read the review, and I thought that the reviewer's points were nonsense, that the riots did not occur in response to sudden news about economic inequality, which is what the reviewer implied. Riots are often very hard to predict. We've gone -- we went decades without a riot. Then, all of a sudden, the Rodney King verdict came, and there was the worst rioting the country had in years.

PINKERThat wasn't in response to economic inequality or frustration. Nor were the riots after the assassination of Martin Luther King. It wasn't as if the latest economic reports from the Bureau of Economic Research came out and started riots. Riots are much more often caused as a response to some perceived insult or harm done to a community, and they're much more a form of revenge than a form of protest over economic inequality.

NNAMDISo where does the decline in violence go from here, Steven Pinker? Are we eventually going to evolve beyond violence completely? Or is it something we will struggle with as long as we are humans on Earth?

PINKERI think we'll continue to struggle. I think we'll -- I don't imagine that we'll ever be able to just dismantle the army or the police force. I think some bit of violence probably will have to be kept in reserve as a deterrent, but I think it can be a lot, lot less. If you just look at, say, the history of relationships between, say, Britain and the United States, or France and Germany, or Poland and Russia, a couple of centuries ago, you would have said they're always going to be at each other's throats.

PINKERNow, the threat of war, say, between Canada and the United States is -- no one would say it's zero, but it's so close to zero that you just don't have to worry about it. And I think the possibility of war between countries could fall into that realm of not worth worrying about for more and more of the world. Could it happen throughout the world, kind of like the 1960s' folk singers sang, the world will put an end to war? I wouldn't bet on it, but it's not impossible either.

PINKEROther things that people thought were a permanent part of the human condition did vanish just as the idealists predicted: legalized slavery being an example, human sacrifice, torture as a form of criminal punishment and so on.

NNAMDIYou serve as chair of the American-Heritage Dictionary's Usage Panel, so you know the power of words. You once said that language is your work. The rest is kind of a hobby. So if this and your other work that strays from language is the sole focus or hobbies, hobbies that produce thoroughly researched 700-plus page books, got to ask, do you ever kick back and watch a hockey game, go fishing, anything a little less rigorous?

PINKERI do like hockey -- I am Canadian -- and bicycling, photography, kayaking, hiking, much of it with my wife, Rebecca Goldstein, also a writer. So we have two writers in the family. We enjoy each other's writing, but we also enjoy physical exercise and nature and walking through the city.

NNAMDIGood to hear. Steven Pinker is a cognitive scientist and professor of psychology at Harvard University. His latest book is called "The Better Angels of Our Nature: Why Violence Has Declined." Thank you so much for joining us.

PINKERThank you for having me.

NNAMDIAnd thank you all for listening. I'm Kojo Nnamdi.