Study Finds Infants Use Logic and Composition Before Learning to Speak
A new study by researchers at Aix-Marseille University-CNRS (France) and PSL University (France) has found that infants as young as 12 months exhibit compositional abilitiesβa foundational cognitive skill once thought to emerge only after language acquisition. The results, published in Communications Psychology, challenge previous assumptions about the timing and mechanisms of early cognitive development. The findings suggest that the human mind is equipped with fundamental reasoning tools well before children can talk.
About The Study: Infants Show Complex Thought Before Speaking
What is Compositionality?
Compositionality refers to the human ability to mentally combine simple elements into complex ideasβlike understanding that βnot greenβ means the opposite of βgreen.β This process underpins language, reasoning, and learning. Historically, it was believed that such mental operations required language proficiency.
Who Conducted the Study?
According to Medical Xpress, the research was led by Isabelle Dautriche and Emmanuel Chemla, cognitive scientists affiliated with Aix-Marseille University-CNRS and PSL Universityβs Γcole des Hautes Γtudes en Sciences Sociales-CNRS. The paper was published in Communications Psychology, a peer-reviewed journal from Nature Portfolio (DOI: 10.1038/s44271-025-00222-9).
Study Methodology
To assess compositional abilities in preverbal infants, the researchers conducted three carefully controlled experiments involving 10- to 14-month-old babies. As infants cannot explain their thoughts, the team used a well-established gaze-tracking paradigm: longer visual attention indicates surprise or a mismatch with expectations.
Experiment 1 tested sentence comprehension. At 14 months, infants were shown simple noun-verb scenarios (βI donβt want the teddy bearβ) to assess their grasp of verbal negation.
Experiment 2 introduced non-verbal negation using facial expressions. An actress displayed the “not-face” β a universal gesture featuring a slight frown and lip inversion β after interacting with an object. (“Not-face” is a term in cognitive science and linguistics for a universal facial expression that conveys negation or rejectionβlike saying “no” without words).
Experiment 3 extended the observation to 10-month-old infants using physical transformations of objects, testing their ability to mentally manipulate visual information.
Infantsβ reactions were measured through eye-tracking software. When events violated expectationsβsuch as a facial expression implying rejection β they looked longer, signaling surprise and cognitive processing.
Innovation: A Shift in Understanding Infant Cognition
This study stands out by demonstrating that compositional reasoning does not depend on language and emerges before infants can speak. Unlike previous studies that examined older children or language-dependent tasks, this work innovatively uses non-verbal cues and physical events to probe early cognition.
Another novelty is the use of facial expressions as linguistic proxies. By showing that infants respond to facial expressions as if they carry grammatical meaning, the study bridges a gap between emotional communication and abstract reasoning.
Key Findings of the Study
1. Compositional Thinking Exists Before Language
Even 1-year-old infants can interpret combinations of elementsβlike negation + objectβsuggesting that the brain processes meaning compositionally from a very early age.
Example: A baby may avoid a food item after seeing a caregiver frown at it, even if no words are spoken.
2. Infants Understand Facial Expressions as Logical Indicators
The study found that infants recognize a βnot-faceβ as a meaningful gesture, not just an emotional display.
Example: When an adult frowns at a toy, infants infer rejection or negation.
3. Cognitive Processing Is Reflected in Visual Attention
Infants look longer at surprising outcomes β such as someone rejecting an object they previously desired β indicating internal reasoning and expectation.
Example: A baby may stare longer if their parent suddenly refuses a favorite item, trying to understand the contradiction.
4. Basic Sentence Composition Develops by 14 Months
By this age, infants can process short sentences with verbs and nouns, even if they canβt yet produce them.
Example: Understanding βnot the teddy bearβ as referring to a rejected item, not just a random object.
5. Mental Manipulation of Objects Appears by 10 Months
Infants can visualize and interpret physical changesβlike transformations of an objectβwithout needing verbal instruction.
Example: A baby might recognize that a toy hidden under a cloth has moved, demonstrating object permanence and compositional logic.
Babies May Reason Before They Speak: What This Means for Early Brain Development
The discovery that preverbal infants display compositional thinking skills has major implications for how we understand early brain development. Traditionally, cognitive scientists believed that the ability to reason about complex ideas and build mental representations of the world was tightly linked to language. This study challenges that view by showing that infants begin combining and interpreting information before they learn to speak.
First and foremost, the findings suggest that core reasoning abilities are already present in the infant mind β independent of language. Babies as young as ten to twelve months can mentally represent an object, apply a transformation (like negation), and respond appropriately when something does not match their expectations. This type of logic was previously believed to emerge only after children began to understand and use language.
Second, the research indicates that infants are not passive recipients of external input, but active interpreters of their environment. When a baby sees an adult frown at an object β a universal facial expression indicating rejection β they do more than recognize the emotion. They appear to integrate that expression into a broader understanding of intention and meaning. This ability to assign structure and interpretation to nonverbal signals reveals a much deeper cognitive capacity than previously assumed.
Third, these compositional skills may form the cognitive foundation that enables language to take root. Once children begin to hear words and phrases, they may already possess the mental tools to break down those verbal inputs and reconstruct meaning from them. Instead of learning from scratch, babies might simply map words onto logical systems that are already operating in their minds.
Fourth, the presence of these abilities in the first year of life points to a critical period of cognitive plasticity. The earlier these abilities emerge, the more time infants have to strengthen them through social interaction, exploration, and play. This finding underscores the importance of enriched, responsive environments that encourage mental experimentation long before formal education begins.
Finally, the study highlights a potential new tool for assessing individual differences in early cognitive development. Eye-tracking techniques, such as those used in this research, could be refined into diagnostic tools to evaluate whether infants are developing typical compositional reasoning abilities. This may help clinicians detect cognitive or developmental disorders at a much earlier stage, opening the door to timely interventions.
In sum, the evidence that infants can reason about the world compositionally before speaking reframes our understanding of how intelligence begins. It suggests that the human brain is wired from birth with a capacity for structure, logic, and abstract thinking β long before language gives that capacity a voice.
Why This Discovery Could Change How We Think About Learning, Healthcare, and AI
The implications of this research go far beyond the nursery. By proving that compositional thinking begins before language, the study opens new conversations across multiple fields β from neuroscience to education, medicine, and even artificial intelligence.
In science, the results support a growing body of evidence that the human brain is wired for structure from birth. If abstract reasoning doesn’t require language, then our models of cognitive development βand even the evolution of language β need revision. It also raises the possibility that other species might share similar nonverbal reasoning mechanisms, inviting further comparative research.
In education, these findings could shift how early learning is approached. Rather than focusing solely on vocabulary building in the first years of life, educators and caregivers might begin encouraging pattern recognition, cause-and-effect exploration, and emotional inference through gestures and play. Environments that reward curiosity and interaction β even before speech β may strengthen a childβs underlying cognitive framework.
In medicine, the ability to assess compositional reasoning through gaze-tracking could lead to earlier and more accurate identification of developmental delays or disorders. For example, if a baby consistently fails to respond to negation cues or doesn’t display surprise at unexpected events, it might signal a need for further evaluation. This could be especially valuable for diagnosing conditions like autism spectrum disorder, where interpretation of social signals is often affected.
The study also resonates with technology and AI research. Understanding how infants combine simple cues into complex interpretations could help engineers design more intuitive and adaptive artificial intelligence systemsβones that learn from context and contradiction in a way that mirrors early human cognition.
And finally, there are broader societal implications. For parents, itβs a reminder that communication begins far earlier than words. The expressions, gestures, and emotional signals exchanged with babies may be laying the groundwork for logic, empathy, and decision-making.
In short, a babyβs curious gaze may carry more meaning than we thought. And thanks to this study, weβre a step closer to understanding just how much is happening behind those wide-open eyes.
Final Thoughts: Language Builds on a Pre-Existing Mental Foundation
The discovery that infants can mentally combine information long before they speak challenges long-held assumptions about the timeline of human cognition. It implies that language is not the origin of reasoning, but rather a tool that emerges from pre-existing mental architecture.
By investigating preverbal minds with scientific precision, the researchers have taken a critical step toward mapping the roots of human intelligence. Future studies may explore whether these abilities are unique to humansβor whether animals and artificial systems might share some of these foundational cognitive traits.
Tools like BabyBright by CogniFit, designed to monitor whether a child is developing according to age-appropriate cognitive milestones, reflect the growing importance of early detection and personalized support. As science uncovers more about early reasoning abilities, such technologies can help parents and professionals better understand and nurture the emerging mind.
As Dautriche and Chemla continue their work, the field anticipates deeper insights into how humans understand the world β even before they can say a single word.
