Developmental and evolutionary origins of the language of thought

Introduction

How do human infants and non-human animals think? Fodor famously framed the idea that human minds operate in a language-like format, a language of thought (LoT), where mental representations compose in the manner of formal language symbols. This allows us to build arbitrarily complex mental structures out of a small set of initial primitive operations.

Evidence and Investigations

Through all areas of cognitive science, there has been rich evidence supporting the idea that a LoT could explain many facets of human cognition. Do infants and animals also have a LoT?

While the existence of a LoT in the absence of language has been questioned for centuries by philosophers, psychologists, and linguists alike, little direct behavioral evidence has been offered for it. These investigations have mainly been confined to close relatives of humans (i.e., great apes).

Project Goals

The overarching goal of this project is to adopt a broad comparative approach to study the developmental and evolutionary origins of the LoT. Our approach is at the intersection of linguistics and psychology:

1. We identify the primitive operations of thought from formal semantic principles and operations realized in language.
2. We empirically test them in:
   • Human adults
   • Infants
   • Baboons (Papio papio)
   • Honeybees (Apis mellifera)

Research Focus

We study the computational architecture of the LoT of infants and animals, starting from their ability to perform simple computations using only a few symbols to the more complex abilities to use functional operators, such as logical connectives, quantifiers, and modals, and to apply pragmatic operations.

Expected Outcomes

The outcome of this project will be an unprecedented cartography of possible LoT primitives and of where they are found in human ontogeny and animal phylogeny.