New Research Illuminates the Emergence of Deceptive Behavior in Infants and Toddlers
A groundbreaking study spearheaded by the University of Bristol has revealed that an astonishing number of children begin to grasp the concept of deception far earlier than previously believed. According to the research, approximately 25% of infants display rudimentary deceptive behavior by the age of 10 months, a figure that escalates to around 50% by the age of 17 months. By the time they reach three years of age, children become notably more sophisticated and frequent in their use of deception, showcasing a burgeoning capacity for cunning and creativity in their social interactions.
Professor Elena Hoicka, who led the study and holds a prestigious chair in Education at the University of Bristol, underscores the significance of these findings in our understanding of child development: “Our research offers compelling evidence that deception is not an advanced skill requiring complex language or cognitive faculties as traditionally assumed. Instead, it manifests in surprisingly simple forms very early in life.” The discovery challenges longstanding notions that deception is a sophisticated social skill only attainable later in childhood, highlighting a continuum of deceptive behaviors that begin during infancy.
Historically, deception has been framed as an intricate cognitive feat that necessitates an advanced theory of mind and linguistic proficiency. However, the Bristol team drew inspiration from ethological studies, noting that deception is not solely a human phenomenon but is observed in numerous non-human species including chimpanzees, capuchin monkeys, antelopes, and various bird species. By integrating insights from animal behavior with detailed surveys of young children, the researchers developed a nuanced framework that identifies the earliest detectable expressions of deception in human infants.
This interdisciplinary approach shed light on how children, even under a year of age, engage in forms of deception that do not depend heavily on verbal communication. As an example, toddlers might pretend not to hear a command such as “time to tidy up,” or they might deny having eaten a forbidden treat like chocolate, even as they betray their actions through subtle nonverbal cues. Professor Hoicka remarks, “These early deceptive acts are often nonverbal and grounded in simple behaviors, indicating a fundamental social-cognitive ability developing well before complex language skills have fully formed.”
The research team amassed data through comprehensive surveys completed by parents of over 750 children aged between zero and 47 months, spanning multiple countries including the United Kingdom, United States, Australia, and Canada. Parents reported a wide spectrum of deceptive behaviors, with some children demonstrating an understanding of deception as young as eight months old. Intriguingly, once a child exhibited deceptive tendencies, such behavior was frequently observed, with roughly half of those children reported to have engaged in some form of deception within the previous 24 hours.
Diving deeper, the study delineated sixteen distinct categories of deceptive acts, ranging from basic mimicry and denial to more complex forms requiring intentionality and theory of mind. Between the ages of 2 and 3, children begin to employ deception in more strategic and context-dependent manners, including secrecy, excuse-making, and distraction. Examples include hiding prohibited objects, feigning ignorance, or fabricating excuses to avoid undesired tasks, such as claiming the need for a bathroom break when they wish to evade tidying.
By the time children reach three years of age, their deceptive strategies expand further, incorporating linguistic nuances and psychological insight. They start employing exaggeration, understatement, or complete fabrication in their narratives. For instance, a child might assert that a ghost was responsible for eating chocolate – a fanciful fabrication that reveals an emerging grasp of storytelling and audience perception. Additionally, children learn to selectively withhold information, a sophisticated form of deception illustrating a more profound understanding of social dynamics.
Such advanced forms of deceit also involve behaviors designed to manipulate the attention and perceptions of others, such as deliberately diverting a caregiver’s focus with comments like “Look over there!” to camouflage forbidden actions. This manipulation is indicative of an increasing cognitive sophistication where children appreciate that others have independent minds that can be influenced through strategic communication.
The implications of this research extend beyond academic curiosity, offering practical guidance for parents and educators. Rather than viewing deceptive behavior as inherently negative, this study reframes lying and deceit as normative developmental milestones. Professor Hoicka advises caregivers to approach these behaviors with an understanding of their developmental context, enabling more effective communication and fostering trust within the parent-child relationship.
From a philosophical standpoint, co-author Jennifer Saul of the University of Waterloo highlights that the morality of deception has traditionally been debated with a focus on adults. The revelations that deception begins at such an early age and evolves in complexity call for renewed philosophical inquiry into the ethics of deception as an innate aspect of human development rather than purely a moral failing.
Moreover, this research offers a valuable framework for further investigation into the neurocognitive substrates that underpin early deceptive behavior. The seamless integration of observational data, parental reports, and comparative studies with animal models lays the groundwork for exploring how brain maturation supports the emergence of theory of mind and executive functions crucial to deception.
Ultimately, this study revolutionizes our understanding of the ontogeny of deception, revealing it as a gradual developmental process that begins in infancy. Recognizing the prevalence and normative nature of early deceptive behaviors empowers caregivers to navigate these complex social dynamics more effectively and encourages continued scientific exploration into the cognitive and social mechanisms that enable humans to engage in such intricate forms of social interaction.
Subject of Research: People
Article Title: ‘The Early Deception Survey (EDS): Its Psychometric Properties in Children Aged 10 to 47 Months’
News Publication Date: 5-Mar-2026
Web References: http://dx.doi.org/10.1016/j.cogdev.2026.101677
Image Credits: Elena Hoicka
Keywords: Social sciences, child development, deception, early childhood, cognitive development, theory of mind, toddler behavior, linguistic development, executive function
