by Vicky Horner, Living Links Center, Emory University

To many people, the words “culture” and “chimpanzee” don’t seem to go together. In fact, apart from starting with the same letter, they seem to have little connection at all. It’s therefore always slightly awkward when I have to explain what I do for a living to someone I don’t know very well. When I tell them that I am a psychologist, but that I work with chimpanzees and study their cultural behavior, I get the distinct impression that some folks think perhaps it is me, and not the chimps, that needs a psychologist!

The looks of surprise and confusion come from the fact that for many people the notion of culture equates with the fine arts, a night at the opera, or a refined palate for expensive wine. The idea of a chimpanzee at the opera sipping on a nice glass of chardonnay is pretty comical, even to me. We can all think of lots of examples of cultural differences between groups of people, but actually defining it in biological terms is a little more difficult. Psychologists, anthropologists and biologists have been arguing about culture for decades, and although we still don’t agree, we are getting a little closer to a definition that keeps most people happy. In order to understand culture, and more importantly to understand the evolution of our own cultural abilities, we need to stop getting caught up in examples of our cultural behavior and focus more on how cultural differences develop in the first place. At the fundamental level, culture is simply a collection of learned behaviors that have been passed on from one generation to the next, such as using chopsticks or knives and forks. For many years culture has been regarded as the hallmark of our species, the ‘human spark’ that separates us from other animals. However, before we can make claims about our own uniqueness, we need to check for similar sparks in other animals, starting with our closest living relatives, the chimpanzees, with whom we share a common ancestor and about 99 percent of our DNA.

One of the Yerkes chimps uses a tool to extract a tasty treat from one of Vicky’s puzzle boxes.

A few years ago, a group of scientists working in Africa got together to compare the behavior of the chimpanzees at their field sites. What they found was rather surprising. At every site, the chimpanzees displayed a totally different pattern of behavior, such as how they use tools and weapons. These differences were not easily explained by differences in habitat or genetics. The scientists therefore thought that perhaps these differences represented chimpanzee cultures, and arose because each group had invented different solutions to similar problems (like dipping for ants with long sticks or short sticks), and that these behaviors were maintained over generations by learning from one another.

However, it is very difficult to study culture and learning in the forest because there are so many variables, so at the Living Links Center we study chimpanzee culture in a more controlled captive environment. We study two social groups of chimpanzees who live in large indoor-outdoor enclosures with climbing structures, grass and toys.  We train one chimpanzee in each group to act as an “inventor” who solves a food puzzle (like how to get the banana out of the box with a stick) in one of two different ways. We then track if and how each new behavior spreads within the groups. These studies are important because they show us that chimpanzees have the brains for culture; they can learn and maintain new behaviors accurately enough to support the reports of culture from the wild. I am not claiming that there is no difference between going out to a Chinese restaurant to practice your chopstick skills and staying home to fish for termites in the back yard, but the fundamental psychological mechanism and the evolutionary driving force behind the two is the same.

Alan tries his hand at a puzzle box, though he’s not quite as motivated as a typical chimp to extract the M&M.

So what does all this mean for the human spark? To me there is no single spark that separates us from chimpanzees; we are intricately connected by our common ancestry. The differences between us arise from thousands of tiny differences in the frequency and contexts in which we do things. For example, we imitate one another constantly; chimpanzees imitate each other sometimes. We take other people’s perspectives on situations frequently; chimpanzees take another’s perspective sometimes. We empathize frequently, they empathize in some contexts. It is all of these little tweaks here and there that make up the human spark.

On a final note, I’d like to emphasize the importance of not falling into the trap of thinking that we are the ultimate and desirable endpoint of evolution. Chimpanzees and humans have both been evolving form our common ancestor for the last 5 million years. They may not be at the opera, but chimpanzee culture is remarkable in comparison to other species. We also have a habit of measuring their abilities against our own human checklist in the quest for the human spark. But what would happen if we measured ourselves on a chimpanzee checklist; would we find a “chimpanzee spark”? How do you measure up to this five-year-old chimpanzee?

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“

Written music — in its modern form

Talk about “oldies” music! Scientists recently uncovered the oldest musical instruments, in the form of carved bone and ivory flutes. The pieces were found in Germany and are at least 35,000 years old. Whoever the early modern humans were who made these musical instruments, they clearly had what we’re calling the human spark! The ephemeral music that our ancient ancestors made of course never made it into the fossil record. But these objects hint at the sophistication of their cultural lives. The flutes are also important because they suggest a major difference between modern humans and Neanderthals – both of whom lived in Europe during this time period. Theories abound to explain why music first emerged: does it relate to our cognitive skills like language, or was it used to attract mates, or to build group unity and social cohesion? Why do you think people played these flutes so many thousands of years ago?

• “New flutes document the earliest musical tradition in southwestern Germany”
  Read the abstract of the scientific paper in Nature.
• Boston.com: “Archaeologists unearth oldest musical instruments ever found”
  This article includes a link to a sound clip of a tune on a reproduction flute.
• Cosmiclog: “Music for Cavemen“
• Wall Street Journal: “Magic Flute: Primal Find Sings of Music’s Mystery”
  This article focuses on music’s correlation with the human spark.

Alan Alda in The Human Spark

Think you know what it means to be human? Can you think creatively, make tools, communicate with the use of language and make moral judgments? Can you use Google and Twitter?

If so, wrangle with these trivia questions to receive free science DVDs.

• When was Charles Darwin born?
• When were the Lascaux cave paintings discovered?
• What animal is our closest living relative?
• What science series did Alan Alda host prior to The Human Spark?

Send the answers to BrainDish, THIRTEEN’s brand new Twitter account.  The thirteenth person to answer all four questions correctly will receive a free DVD box set of our INNOVATION series and a box set of The Human Spark when it premiers.

Here’s how it works:

1. Tweet your answers to @BrainDish in the following format:
@BrainDish 1) dd/mm/yyyy 2) dd/mm/yyyy 3) animal 4) series name

2. Don’t forget to follow us @BrainDish for future contests and updates.

3. Sit back and wait to see if you’re a winner.

That’s it!  So simple, even a chimp could do it!

BrainDish is THIRTEEN Science’s official new Twitter feed. We’ll be tweeting out our musings on the latest science and technology news you didn’t know you needed to know. It’s also a great way to stay up to date on the behind-the-scenes action and upcoming programs and contests from THIRTEEN’s science department.  So put your money where your mouth is, your mind where your thumbs are, and give us a tweet!

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.