Gesture, Brain and Language: Gillian Forrester on The Life Scientific

Summary

The Life Scientific talks with Gillian Forrester, a professor of comparative cognition, about how humans may have language roots in gesture, hand movements and problem solving rather than speech alone. Tracing her work from gorillas in Gabon to newborn babies at home, the interview explores how gesture, body movement and tool use share underlying brain processes that shape language and cognition. Forrester discusses facial expressions, social dynamics, and the surprising pattern of brain lateralization that links dexterity and language, including how some people differ in their typical brain organization and what that might mean for social interaction.

• Gestural-language theory contrasts with speech-first ideas, proposing that physical action and gesture preceded spoken language.
• Puzzle-box experiments show that physical problem solving engages syntax-like processing in both humans and great apes.
• Early motor development and “general movement” patterns in babies can reflect later social and linguistic outcomes.
• Public engagement and science communication play a crucial role in translating complex findings for broader audiences.

Gestures, Language and the Brain

The podcast features Gillian Forrester, a leading figure in comparative cognition, who investigates how movement, gesture and problem solving relate to language development. Forrester’s perspective emphasizes that language may have roots in the way animals and humans use their bodies to communicate and solve tasks. Her work spans gorilla groups in Africa, living rooms with new parents, and large-scale public events like Glastonbury to understand how movement and communication emerge in social contexts. The discussion highlights how gesture, not just vocalization, can carry meaning and how the brain may have evolved a distributed system for processing gesture and speech alike.

Two Competing Theories: Gesture and Tool Use

Forrester outlines two primary theories of language origins. The gestural language theory proposes that early language began with visual and manual gestures, with the left-to-right evolution of speech as hands became freed by bipedalism. The tool-use theory argues that the organization of sequential actions—what she terms “physical syntax”—precedes and informs verbal syntax. To test these ideas, she designs puzzle boxes that require users to manipulate shelves and gears to retrieve a prize, arguing that if both humans and apes can solve such tasks, it supports the idea that physical sequences underpin language syntax before vocal language.

Puzzle Boxes: A Window into Syntax

In a live demonstration, the host and Forrester attempt a box with moving parts and a hazelnut. The test reveals that young children struggle with complex, sentence-like syntax, while some great apes manage the hardest syntax problems. This cross-species performance suggests that the cognitive mechanisms underlying ordered action and sequencing are shared and may have existed before humans fully developed speech. The implication is that grammar-like sequencing could be rooted in physical action rather than solely in the mouth.

Lateralisation: The Two Half-Brains at Work

The discussion moves to lateralisation, the division of labor between the brain’s two hemispheres. Forrester explains that many people display a canonical left-brain language dominance with corresponding motor control patterns, but a substantial minority show reversed or atypical patterns. She notes correlations between reversed lateralization and social processing differences, and mentions higher prevalence of ADHD and certain social-cognitive traits in this group. The take-home message is that dexterity, language and social cognition are tightly linked through brain organization, and that there is considerable variation in how brains are structured to handle social information.

From Babies to Gorillas: Motor Development as a Window into Social Skills

A significant part of the conversation centers on the Baby at Birkbeck and the Baby Girl project. Forrester describes how early reflexive movements in unborn and newborn babies—writhing movements with structured, quadratic quality—may predict cognitive and social outcomes. Families contribute weekly video data to quantify movement diversity, aiming to develop an early detection system for developmental trajectories that could inform parental guidance and clinical screening.

Public Engagement and the Me Human Project

The interview also touches on public science communication. Forrester emphasizes that engagement with the public can have a greater impact than some traditional scientific publishing. Her Me Human Project invites the public to reflect on what it means to be human, fostering an inclusive dialogue about animal cognition and human uniqueness.

Reflections on Human Uniqueness and Animal Intelligence

Forrester argues that intelligence should not be treated as a human monopoly. She points to examples where animals outperform humans in certain tasks, such as rapid facial recognition or complex pattern discrimination, and suggests that humans are best viewed as individuals with a particular ecological niche rather than as inherently superior thinkers. The conversation closes with a reaffirmation of humanity as part of the great ape family, underscoring a shared evolutionary heritage and the value of cross-species comparisons for understanding our own minds.