Watch below to learn more about her studies on chimp emotions and what these studies can tell us about the human spark.

Heat treatment transforms the poor quality silcrete on the left into the ideal tool making material on the right. (Photo by Kyle Brown / South African Coast Paleoclimate, Paleoenvironment, Paleoecology, Paleoanthropology Project © Copyright Arizona Board of Regents)

Pyroengineering. A big word for what early modern humans learned to do at least 72,000 years ago, according to researchers.

A team of archaeologists says that ancient humans harnessed the power of fire to transform stone raw material into an improved form for tool making. It’s next to impossible to fashion sharp stone blades from a stone called silcrete as it naturally occurs. But if silcrete is heat treated, it can then be worked into advanced tools.

This complex technology is another example of that behavioral modernity we are calling the Human Spark – and it’s occurring on the southern tip of Africa tens of thousands of years earlier than the Human Spark is evident in Europe.

When the Human Spark team filmed with Arizona State University’s Curtis Marean, he told Alan Alda about his group’s discovery at Pinnacle Point in South Africa. Watch this video to hear how the scientists figured out the secret of the silcrete.

More information:

• ScienceNews: “Fire Engineers of the Stone Age“
• New Scientist: “Earliest Fired Knives Improved Stone Age Tool kit“

The crew films Randy Buckner and Rebecca Saxe in the control room while Alan lies in the MRI machine, having his brain imaged. Photo: Maggie Villiger

By Graham Chedd

Now, I don’t want to get too excited, and I don’t want to give too much away – after all, we want you to watch our shows when they are broadcast. But I think we’ve just seen the first signs of the Human Spark – right inside Alan’s head.

Alan takes a look at the fresh pictures of his own brain. Photo: Larry Engel

We spent the day at MIT’s McGovern Institute, where Alan’s brain was being scanned while doing tasks set for him by MIT’s Rebecca Saxe and Harvard’s Randy Buckner.  Our filming Alan while he’s having his head examined is nothing new, by the way; in the days of Scientific American Frontiers we must have had him in and out of some half dozen MRI machines over the years. In fact, Randy remembered one of those shows, where another Harvard researcher had told Alan that he had a “plump hippocampus,” the brain region involved in helping lay down memories. Randy confirmed Alan’s hippocampus is still plump; in fact, Randy told Alan that he wouldn’t have guessed his age from looking at his brain.

There’s a story behind why we filmed with both Randy and Rebecca, who – while both rising stars in the neuroscience field – are actually working on two apparently unrelated special skills we humans possess. Rebecca has made her name by studying the brain regions involved in thinking about other people, especially thinking about what they are thinking about. Randy, meanwhile, has been studying how we think about the past, and more recently, how we think about the future.

As Rebecca told Alan: “I saw Randy giving a talk about thinking about the past and I looked at these pictures [of the brain] and I thought, ‘that looks really familiar.’ And so I went back to Randy afterward and I said, ‘I’ve got pictures that look a lot like those pictures.’ And so since then we’ve been working together to try to ask: what’s in common? What’s the same about thinking about your own past, your own future, and also other people?”

Well, you’ll have to wait for the answer until The Human Spark is on the air. But I can tell you that Alan had to perform two very different tasks in the scanner. One for Rebecca involved figuring out what a character in a video cartoon was thinking. (Rebecca tested children on the same kinds of social cognition tasks Alan tried. Read about her latest study on how these skills develop as kids mature.) The other for Randy, a word task, actually had nothing to do with what Randy was really looking for – which was what Alan’s brain was doing while he was simply waiting in the scanner, staring at a cross hair and letting his mind wander. What our brains do when we’re doing nothing very much is one of the hottest topics in neuroscience just now. As Randy puts it succinctly: “We think we’re seeing the idle brain not being so idle.”

Rebecca prepares to slide Graham into the MRI for his first ever brain scan. Photo: Larry Engel

I’m going to leave it to you to work out why Alan and the crew found these ideas so exciting, with the not very subtle hint that figuring out what others are thinking on the one hand, and being able to mentally time travel on the other, are two skills which, if not uniquely human, are in humans uniquely powerful. And the discovery that they appear to involve related brain areas – well, Sparks are flying.

As a postscript to the day, Rebecca offered me a chance to have my brain scanned in the McGovern Institute’s very fancy new MRI machine, which looks, by the way, a little like a set for “House.” Now this is something I’ve been given the chance to do many times over the years, going back to not long after MRI machines were invented. I’ve always said no, reasoning that my brain might turn out to be a little less than the perfectly honed machine I’ve always assumed it to be. But this time, inspired by Alan’s pristine hippocampus, I allowed myself to be slid into the tube and tried to think of nothing. You can see the results below.

I have a sneaky feeling Randy thought Alan’s brain looked better.

Sound Recordist John Garrett and Director/DP Larry Engel size up shooting conditions.

The day we had scheduled to film with Harvard University’s Dan Gilbert dawned beautiful – but frigid! If we were planning to shoot in a lab or office, that wouldn’t really matter, but the idea was to film Alan Alda and Dan in conversation outside. We needed a compelling discussion because their talk focused on a topic that was crucial to our Human Spark story, but we also wanted an exciting location that added some visual flair to the film and subtly illustrated the breadth of our human abilities.

Producer Graham Chedd thought a chat en plein air would add the visual variation we needed and be a big improvement over the “two-guys-sitting-on-a-couch”-type shot that is too often the easy default. The goal was to position Alan and Dan in the middle of a footbridge that spans the Charles River between Boston and Cambridge. Luckily they were both very good sports and we had gloves!

Do you know who Dan is? If you don’t know him from his book Stumbling on Happiness [more info at Wikipedia], perhaps you saw his quote on a Starbucks coffee cup:

“The human brain is the only object in the known universe that can predict its own future and tell its own fortune. The fact that we can make disastrous decisions even as we foresee their consequences is the great, unsolved mystery of human behavior. When you hold your fate in your hands, why would you ever make a fist?”

In this video Dan talks about distilling his work down to a 59-word message – an ability closely tied to the Human Spark.

Watch Hauser explain to Alan Alda his concept of humaniqueness – and how we can draw on a multitude of talents to solve a problem, whereas other species are limited to just a few.

When Amanda Henry went through airport security in Washington on her way to Boston she made the inspector nervous when her bag revealed dental instruments – apparently the security officer hates going to the dentist. The officer may have been even more freaked out if she knew the teeth Amanda was on her way to clean with her dental picks belonged to a 100,000-year-old.

A very famous 100,000-year-old at that – at least in archeological circles. The teeth are still all neatly in place in a skull now at the Peabody Museum of Harvard University [tons of images here], where it has resided in secure climate-controlled storage since it was unearthed in the 1930s from a cave in Mount Carmel, in present-day Israel. We had met the skull the day before, when Dan Lieberman had arranged for it to be brought out of storage and introduced to Alan.

Known as Skhul 5, the skull is the oldest known human with almost modern features, and so plays a pivotal role in our story. He poses the central puzzle we’re trying to get to the bottom of: people looked like us apparently long before they started behaving like us – at least according to the commonly accepted view that the modern human mind – with what we are calling the Human Spark – didn’t evolve until tens of thousands of years after the owner of the Skhul skull and his like lived in the Middle East – most likely alongside, or at least at the same time as, their cousins the Neanderthals.

The Human Spark camera rolls while Amanda demonstrates her dental scraping techniques to Alan. Photo: Maggie Villiger

As we’d just been learning from Alison Brooks, it’s now looking increasingly likely that the Human Spark in fact started to glimmer much earlier in Africa, perhaps even before the ancestors of Skhul 5 made their way north. So archeologists would love to know as much as possible about how Skhul 5 lived. It was Alison who told us about Amanda, a student of hers at George Washington University, who – armed with her dental picks – was going to demonstrate to Alan how she’s figuring out what Skhul 5 ate.

After carefully removing the skull from its padded box, Amanda showed us how she very, very gently scrapes dental plaque from the skull’s molars (much more gently than your oral hygienist cleans yours).  Plaque, she explained, is the perfect material to preserve microfossils from the plants Skhul 5 ate – starch grains and tiny silica bodies called phytoliths that Amanda will be able to identify under the microscope and tell what plants they came from.

Amanda’s care in her scraping wasn’t only because, as she reminded us, the skull is priceless, but also because, “I have to leave some plaque behind in case somebody comes up with a different way for studying it in the future.”

Alan wanted to know if she poked around in his teeth, could she find out what he’s eaten.

Amanda: Well it depends, how good are you at brushing and flossing?

Alan: Oh just great, yes.

Amanda: I’ve actually done some experiments where you eat whatever you normally eat for breakfast, lunch and dinner. At the end of the day , you take one of these dental picks…

Alan: And you could say what the person had eaten?

Amanda: Some of it, sure.

Alan: No kidding.

Amanda: It’s quite easy. It’s not just in the plaque. It’s in any of the pellical, basically the scum that builds up on your teeth. As that hardens into plaque then it’s more permanently kept on your teeth. I don’t know, actually, how far back I’d be able to tell what you ate, whether I could just tell this morning what you had for breakfast, or what you had three weeks ago.

Fortunately for Amanda, and despite the astonishingly good shape of Skhul 5’s teeth, he lived a good long time before the invention of dental floss, so she has high hopes of discovering what he ate 100,000 years ago.

Alan summed up the reaction of all of us: “Astonishing.”

- Graham Chedd

Alan Alda recently chatted with Steven Pinker in his office in the Psychology Department at Harvard University. Much of Pinker’s research has focused on language – and not surprisingly language is central to his conception of what makes us human.

Watch this video clip to learn more about three big things Pinker thinks set us apart from other animals.

Alan looks on as Larry gets some closeup shots of chimps through the glass. Photo: Maggie Villiger

We hit the ground running. Alan had a quick press conference at the zoo, just by the chimpanzee area, and as soon as it was over, and before I was ready with the camera (I wanted to add a polarizing filter and matte box to cut down on reflections in the glass barrier), Alan and Brian Hare were immediately engaged in conversation. As in all of our shoots, this was a genuine discussion between Alan and the scientist and there’s no going back once their exchange gets rolling!

Reflections from the sun, smudges from the chimps – shooting at the glass enclosure had its challenges for Larry Engel. Photo: Maggie Villiger

So, we went to work. I had to be careful of our reflections but it was not an easy task and we picked up Graham, Maggie, John and me every so often. Further, with a small viewfinder, it was extremely hard to notice reflections in the background — unless there was movement. Nonetheless, Alan and Brian were talking about what we think chimps are thinking and how could we come to understand their minds better in order to understand ours better. And this was a great conversation.

Since Brian and Alan were talking to one another before the glass, they couldn’t quite see the chimps behind them. It was fascinating to listen to the conversation concerning our nearest living relatives and their framework for perceiving the world and communicating with us and one another — all the while watching them through the viewfinder observing Alan and Brian conversing. Every so often a chimp would sit down and simply stare at them. It was a wonderful image and a great moment. A few times one would come running down the path and bang against the glass, startling the two deep in discussion and making them laugh.

I must admit that I find zoos generally depressing. This is a feeling that I’ve had since I was a boy and my parents took our family to the Bronx Zoo many years ago, well before zoos changed much of the way they housed animals. But here, I better understand that in many ways zoos are critical to survival for many species and are also critically important to our quest to understand better who we are and how we are connected to other animals with whom we share the planet. I only wish I could meet our relatives face-to-face without the barrier of the glass. We have a chance for that if we get to Africa.

- Larry Engel
Director and Director of Photography

Check out a tiny excerpt from Alan’s remarks at the press conference: