Hands, tools, and words, oh my!

It is relatively easy to list things that make our species, Homo sapiens, unique. From modest biological traits like hairless bodies and walking on two feet, to amazing things like culture, technology, and language, it is quite clear that we became some pretty quirky animals over the course of our evolution. Exactly how and why our lineage became ‘human’ is a much more difficult matter to investigate, especially when we consider some of the more complex behaviors on our list.

For example, perhaps one of the most interesting questions we have about ourselves as a species is: how and why did language evolve? Language is a unique behavior that all modern humans share, and we rely upon it so heavily in our lives that it’s difficult to imagine a world without it. However, scientists and philosophers interested in the evolution of language have been struggling with a very large methodological problem for centuries—words and brains don’t fossilize! Still, language is no evolutionary accident. Through centuries of study in many fields including psychology, anthropology, and others, we have learned that language is closely related to other uniquely human traits—like the production and use of technology, and curiously enough, handedness—that do preserve in the fossil record.

It is likely that you and most of the people you know are right-handed, but this uniquely-human behavioral trait is not something that we regularly notice or think about, even though it can actually tell us something about how our brains work when we hear and produce language. Likewise, most of us immediately imagine ‘bows and arrows’ and other technologies when we think about human prehistory and evolution. However, it might surprise you to know that many of the language areas in the brain are also used for making and using a stone tool and that technology itself might be exactly what our ancestors needed to build language-ready brains! For scientists interested in these topics, what’s most important is that the evolution of technological skill and perhaps even the evolution of handedness itself, preserve pretty well in things like fossil bones and tools (like the Acheulean handaxe pictured above). This allows us to make inferences about the brains and behaviors of our ancestors, including whether or not they were capable of using language.

In collaboration with the Stone Age Institute, researchers in the Cognitive Science Program and in the Department of Anthropology at IU are trying to understand how our hands, tools, words, and brains became such an extraordinary system over several millions of years. Funded by a recently-awarded $3.2-million grant from the John Templeton Foundation, the team will spend the next three years, both in the lab in the field, conducting neuroimaging studies on various aspects of language and tool making and collecting and analyzing fossils and tools which may tell us more about the ‘when, how, and why’ of human brain evolution. They hope to shed some light on exactly what types of questions archaeology can answer about human cognition and language, and set the groundwork for future research in years to come.

Edited by Mark Juers and Karna Desai.