Time to Think

"It’s sometimes said that the Information Age started in the 1970s…but nature discovered the utility of information long before we did," said philosopher Jenann Ismael of Columbia University, in New York City, speaking at FQXi’s sixth international meeting, in Tuscany, Italy in 2019.

Ismael was pondering an age-old question: What separates humans from other animals? For centuries philosophers, scientists and theologians have pointed to our rationality as the defining factor. But Ismael argues that they have overlooked the role culture has played in our rise as the dominant species on the planet. She has been awarded an FQXi grant of over US$100,000 to investigate the emergence of intelligence from nature through information processing and the development of culture. The mechanism, she posits, is linked to fundamental physics, with thermodynamics—the scientific framework originally developed to understand the flow of heat and energy in engines—and its relationship to the arrow of time, playing a crucial part.

"It’s a project that spans the levels, from physics all the way up to culture," says Ismael. "It’s really about that explanatory arch that runs through everything."

One of the most stubbornly persistent ideas about our species is the line of demarcation we draw between ourselves and all other species on the planet. And the line has traditionally been predicated on our unique rationality, especially our ability to think in abstract terms. The Catholic Church in the Middle Ages went so far as to adopt Aristotelian metaphysics to posit a unique ’rational soul’ that distinguishes each individual from the rest of creation. Darwinian evolution undermined the contention that a soul distinguishes us from other animals, however. The continuing study and exploration of the intelligence of other animal species in recent decades—including crows, whales, and elephants—has put further pressure on the notion that reasoning is unique to Homo sapiens, and alone can be taken as our defining characteristic.

But if not rationality, then what? Ismael’s alternative view that culture is significant was inspired by the work of John Maynard Smith, a British mathematical biologist, and Hungarian evolutionary biologist Eörs Szathmáry. In the late 1990s they argued that major evolutionary transitions involve changes in the way information is stored and transmitted (Nature 374, 227–232 (1995)). The leaps the universe has made, from non-life to life, from chemical reaction to mind, and from individualism to society all occurred when information previously lost to the environment as noise was harnessed to do causal work.

Footprints in the Sand

Over an evolutionary timescale, there’s a developmental trajectory that leads from simple creatures that respond to local traces in the environment—the smell of prey, the sound of danger, and so on—to ones with increasingly sophisticated ways of tracking and processing and communicating information. Creatures with memories that can track regularities spotted in the macroscopic world in the present moment, and those that have ways of processing information and understanding its dependence on the past, will have a selective advantage. For instance, seeing a footprint in the sand and being able to recognise that means that an animal recently passed by, will help those hiding from predators and those hunting prey. "We are the product of that developmental trajectory," Ismael says.

Here Ismael makes the connection to fundamental physics. At the microscopic scale, physical laws are reversible; they look identical whether they play out forwards or backwards. Macroscopic processes, however, follow an arrow of time that points from the past to the future. In thermodynamic terms this is often framed in terms of a quantity called entropy, a measure of the disorder of a system. The second law of thermodynamics says that the entropy of an isolated system cannot spontaneously decrease. In other words, left to their own devices, things tend to get messier. Footprints in the sand will wash away; footprints don’t spontaneously appear on the beach as the wind blows the sand. It’s thus only because of the existence of a thermodynamic arrow of time that footprints provide a macroscopic record of what happened in the past, rather than a record of what will happen the future.

"The macroscopic state of the world where there’s a thermodynamic gradient contains the imprint of its macroscopic history," says Ismael. The information contained in the macroscopic environment is then available to other systems to use as a basis for their own behavior.

Ismael outlined her theory at FQXi’s Tuscany conference in 2019:

Cosmologist Sean Carroll of Caltech in Pasadena, thinks that Ismael’s interdisciplinary approach is promising. "Physical laws are purposeless and abstract, while the world we see is rife with intention and meaning," he says. "It is clear that the answer will involve information, thermodynamics, and emergence."

What’s special about human intelligence, then, is its ability to handle information about the past. "Human beings can gather large bodies of information, process it in complex ways, and put the information to unlimited, flexible use," says Ismael. "If you look at simple precognitive creatures, you can already see the beginnings of what they’re doing as they’re exploiting information, for example to metabolize energy, to take advantage of feeding and mating opportunities."

At first blush, it looks like you can trace a continuous development from other animals to humans, if you only consider simple physiological changes. But Ismael has dug deeper. "There’s something that’s going on that seems to be an important kind of transition, not just a continuous enhancement of abilities," she notes.

The key was realizing that it’s not just the amount of information a mind can process that is important, it is also the kind of information needed to recognize macroscopic records of history: humans have a sense of the past and future. "We think in and about time," says Ismael. "We have a conception of ourselves as temporally extended creatures, we are able to recognize quite abstract temporal patterns, to form and carry out plans that demand both foresight and hindsight." While studies suggest that some animals also have a temporal sense, it is not anywhere near as pronounced as it is in humans.

Cultural Evolution

Ismael goes further arguing that it’s the ability to pass information based on past experience to other humans, handing down knowledge through generations, that makes humans stand out. And that brings us to the development and evolution not of single entities but of culture. Now you’re thinking of the unit that’s collecting and utilizing information as not an individual human mind, but several minds at the level of culture.

"We are smart, and we have abilities that other creatures don’t have, just in terms of the onboard machinery, says Ismael. But she points out that this would not get any of us very far if we each had to solve all the problems needed to survive, such as how to build shelter, cultivate food, or treat illnesses, from scratch. "The fact is that we rely on, and we utilize these kinds of collected and stored solutions to problems that are accumulated cross-generationally," she says.

Daniel Dennett, a philosopher at Tufts University in Medford, Massachusetts, thinks Ismael is on target. "That is the way to think about the power of human culture, which permits us, both as individuals and as teams or colleagues or associations or…armies, to accomplish ends that dwarf the projects of all other species," he says. Dennett notes that the same ideas about culture have been formulated by others in the past, but in different ways, with the focus on the power of meta-representation, the power of thinking tools, or the power of language, for example.

Carlo Rovelli, a physicist at Aix-Marseilles University in France, who himself has worked on connecting evolution to physics, is also impressed. Ismael "has been repeatedly capable of finding the correct relation between the scientific picture of the natural world and the ’high level’ notion that we use to make sense of reality both in our common sense view and in the humanities," he says.

The role of human temporal perception in the work fascinates philosopher Craig Callender, of UC San Diego, an expert on time. "Since the ability to mentally time travel is connected to our finding regularities in the world, this step in our development is a huge one," says Callender. "Researchers thinking about culture often focus on tools and language, but this potentially deeper feature of our development has been right in our faces."