In plain terms, private speech is the out-loud talking children do to themselves — narrating a drawing, muttering through a tricky puzzle, coaching themselves with "no, the big piece goes here first." It looks like a quirk, but it is one of the engines of thinking. The psychologist Lev Vygotsky argued that this self-talk is how children take the guiding voice of a parent or teacher and make it their own: first they think out loud, then in whispers, and finally silently, "in the head," as inner speech. This article explains what private speech is, how Vygotsky and Piaget disagreed about it, the stages by which it goes silent, what it does for self-control and problem-solving, and what current research — from classrooms to ADHD to tablets — has found.
Private speech is overt, audible speech that children direct at themselves rather than at a listener, typically while playing or working on a task. On Lev Vygotsky's account, it is a developmental waypoint: speech begins as a social tool for communicating with others, turns inward to become a tool for guiding one's own thought and behavior, and is gradually internalized into silent inner speech, or verbal thinking (Vygotsky, 1986). It is therefore the observable, audible middle of a journey from talking with others to thinking to oneself — and because it is audible, it gives researchers a rare window onto the development of self-regulation and executive function (Winsler, Fernyhough, & Montero, 2009; Berk, 1986). The idea has its roots in Vygotsky's broader sociocultural theory and connects closely to the zone of proximal development and scaffolding (Vygotsky, 1978).
What Is Private Speech?
Private speech is self-directed speech: the child is both the speaker and the intended audience. It is usually defined as overt, audible speech not addressed to another person, in contrast to inner speech, which is fully internal, silent verbal thought (Winsler, Fernyhough, & Montero, 2009). A four-year-old assembling a puzzle who says "where does this one go… try the corner" is producing private speech; the same child a few years later, thinking those words without moving her lips, is using inner speech.
What makes the phenomenon interesting is not the talking itself but what it reveals. Vygotsky proposed that the function of private speech is self-regulation — children use it to plan, to direct and sustain attention, to pace themselves, and to monitor and correct their own performance, much as an adult had earlier done for them out loud (Vygotsky, 1986; Diaz & Berk, 1992). Because the speech is audible, it lets researchers observe a regulatory process that, in adults, has gone silent and hidden — which is why private speech has become a central object of study for the development of executive function (Alderson-Day & Fernyhough, 2015).
Two Views: Piaget's Egocentric Speech and Vygotsky's Private Speech
The behavior was first described not by Vygotsky but by Jean Piaget, who in 1923 recorded young children talking aloud to no one in particular and called it egocentric speech (Piaget, 1959). For Piaget, this talk reflected the young child's cognitive immaturity — an inability to take another's perspective — and it was developmentally unimportant: a kind of verbal accompaniment that would simply fade away as the child became more socially and cognitively competent.
Vygotsky agreed about the observation but disagreed sharply about its meaning. He argued that this self-talk does not disappear at all; it goes underground, transforming into inner speech rather than dying out, and that far from being a useless symptom, it performs the crucial work of self-guidance (Vygotsky, 1986). To test this, Vygotsky manipulated children's working conditions — for example, placing a child among others who could not understand them, or removing the possibility of being heard — and found that private speech dropped when its social-regulatory point was undermined, which fit a functional account better than Piaget's immaturity account (Vygotsky, 1986). Decades of subsequent empirical work have largely favored Vygotsky's interpretation: private speech follows an orderly developmental course, is most frequent when it is most useful, and is associated with better self-regulation rather than with deficiency (Berk, 1986; Diaz & Berk, 1992).
The Developmental Trajectory: From Out Loud to In the Head
The hallmark of private speech is that it follows a predictable path of internalization. Self-directed speech emerges in toddlerhood, becomes frequent and fully audible during the preschool years (peaking around ages four to five), then quiets into whispers, mutterings, and lip movements during the early school years, before finally becoming silent inner speech (Winsler & Naglieri, 2003; Diaz & Berk, 1992). The transition is gradual and overlapping rather than abrupt, and it does not vanish entirely even in adults: studies observing children and adolescents on cognitive tasks still find overt self-talk in a substantial minority of those aged 11 to 17 (Winsler & Naglieri, 2003).
What Private Speech Does: Self-Regulation and Executive Function
If Vygotsky was right that private speech is a tool for self-guidance, then it should appear most when guidance is most needed — and it does. A robust and much-replicated finding is that children produce more private speech on harder tasks: as task difficulty rises, so does the rate of self-directed speech, exactly as a regulatory account predicts (Fernyhough & Fradley, 2005). Private speech is also tied to the management of attention and effort; in classic naturalistic work, children's task-directed private speech was related to how closely they attended to their work (Berk, 1986).
In contemporary terms, private speech is understood as part of the development of executive function — the family of skills (working memory, inhibitory control, cognitive flexibility, planning) that underlie self-control (Winsler, Fernyhough, & Montero, 2009). The verbal self-guidance a child practices out loud becomes, when internalized, a means of silently directing one's own cognition. That internalized endpoint — inner speech — has itself been implicated in working memory, task-switching, planning, and the monitoring of behavior, and reviews now treat private and inner speech as two developmental phases of a single, functionally significant verbal system (Alderson-Day & Fernyhough, 2015).
A Worked Example: Talking Through a Hard Puzzle
Picture Maya, age five, working on a shape-sorting puzzle that is just beyond easy for her. On the simple pieces she works silently. When she reaches a section that genuinely stumps her, her private speech surges — the difficulty pulls it out of her, just as the research predicts (Fernyhough & Fradley, 2005). She narrates and plans out loud: "This one's too big… try the corner first… no — turn it." The speech is doing regulatory work: it focuses her attention, breaks the problem into steps, and catches her own error ("no — turn it") the way an adult's coaching once did (Vygotsky, 1986; Berk, 1986).
As the year goes on, the same regulatory talk grows quieter. Maya begins to whisper the steps, then merely move her lips, then fall silent while her eyes and hands still show the same deliberate, planful pattern — the audible scaffolding has gone inward (Winsler & Naglieri, 2003). By the time she is eight, the puzzle that once made her talk aloud is solved in silence, guided by inner speech she no longer needs to voice (Vygotsky, 1986). The arc — from an adult guiding her, to Maya guiding herself out loud, to Maya guiding herself silently — is the internalization of self-regulation in miniature.
Private Speech Compared With Related Concepts
| Concept | What it is | Relationship to private speech |
|---|---|---|
| Social (communicative) speech | Speech addressed to and intended for another person | The developmental origin; private speech splits off from it as speech turns inward |
| Egocentric speech (Piaget) | Piaget's term for children's non-communicative self-talk, viewed as a sign of immaturity that fades | The same observable behavior, interpreted differently; Vygotsky reframed it as functional and internalizing |
| Inner speech | Silent, internalized verbal thought | The mature endpoint into which private speech develops |
| Self-instructional training (Meichenbaum) | A clinical technique that teaches children to guide their behavior with deliberate self-statements | An applied intervention built on the self-guiding function of private speech |
| Self-talk (sport, clinical, everyday) | The broad family of verbalizations directed at the self across the lifespan | The umbrella category; private and inner speech are its developmental core |
Applications
Because private speech supports self-regulation, the most direct educational implication is that it should usually be allowed rather than suppressed: a preschooler muttering through a task is not misbehaving but self-guiding, and quieting them can remove a support they still need (Diaz & Berk, 1992). The phenomenon is especially relevant to ADHD. Children with ADHD tend to produce more task-irrelevant private speech and to be somewhat delayed in internalizing it, consistent with the idea that verbal self-regulation is developing atypically (Berk & Potts, 1991); and recent work with adults finds that those with more ADHD traits report more self-directed speech, which the authors interpret as a possible coping or camouflaging strategy (Benfield & Cole, 2026). Private speech has likewise been studied in autistic children and in second-language learners, who often use audible self-talk while working through problems in a new language. A more contemporary applied concern comes from how children play: an experimental study found that completing the same task on a tablet rather than with physical materials reduced children's self-regulatory private speech — a "digital bubble effect" with possible implications for executive-function development (Bochicchio, Keith, Montero, Scandurra, & Winsler, 2022).
Contemporary Research
Modern research has moved well beyond establishing that private speech exists, toward mapping its functions, measuring its internalized form, and situating it in a larger picture of self-directed language. The development of executive function and self-regulation remains the central organizing theme, anchored by the major edited volume on the subject (Winsler, Fernyhough, & Montero, 2009). A parallel strand studies the silent endpoint: a comprehensive review of inner speech integrated its development, cognitive functions, phenomenology, and neurobiology, and proposed a multicomponent model — while candidly noting how difficult silent speech is to study (Alderson-Day & Fernyhough, 2015). More recently, a large interdisciplinary review drew together the once-scattered literatures on self-talk across developmental, clinical, sport, and educational psychology into a single transdisciplinary model, explicitly positioning private and inner speech as the developmental core of self-talk (Latinjak et al., 2023). Active questions now include how modern, screen-mediated play environments affect self-talk (Bochicchio et al., 2022) and how self-directed speech functions across the lifespan and in atypical development, including ADHD (Benfield & Cole, 2026).
Criticisms and Open Questions
The construct is well established, but real difficulties remain. The most fundamental is measurement: private speech is only partly observable, and once it goes silent there is no direct way to watch inner speech, so researchers must rely on indirect or self-report methods whose validity is debated (Alderson-Day & Fernyhough, 2015). A second is the strength and consistency of the performance link: while private speech reliably rises with task difficulty, task-relevant self-talk does not always correlate with better task performance, and findings are mixed enough that simple "more talk equals better" claims are unwarranted (Bochicchio et al., 2022). A third is that much of the evidence is correlational — private speech is associated with self-regulation, but isolating its causal contribution from the general growth of language and cognition is hard. Finally, there is substantial individual variability in how much, and for how long, children rely on overt self-talk, which complicates both norms and predictions and cautions against treating any single child's pattern as diagnostic.
Key Researchers
- Laura E. Berk — Illinois State University (Distinguished Professor Emerita of Psychology); the foremost empirical researcher on children's private speech and its links to attention, task performance, and self-regulation, and co-editor of the field's defining volume (Berk, 1986; Diaz & Berk, 1992).
Faculty - Adam Winsler — George Mason University (Professor of Applied Developmental Psychology); a leading researcher on private speech, verbal self-regulation, and executive function, and co-editor of the major modern volume on the topic (Winsler & Naglieri, 2003; Winsler, Fernyhough, & Montero, 2009).
Faculty - Charles Fernyhough — Durham University (Professor of Psychology); a leading figure on the development from private to inner speech and on the cognitive science of inner speech (Fernyhough & Fradley, 2005; Alderson-Day & Fernyhough, 2015).
Google Scholar · Faculty - Lev S. Vygotsky (1896–1934) — Originated the account of private speech as the internalization of social speech into inner verbal thought, and its role in self-regulation (Vygotsky, 1986).
- Jean Piaget (1896–1980) — First described children's self-talk, which he termed egocentric speech and interpreted as a sign of cognitive immaturity — the view against which Vygotsky's account was framed (Piaget, 1959).
Key Terms
| Term | Meaning |
|---|---|
| Private speech | Overt, audible speech that children direct at themselves rather than at a listener, typically while playing or working. |
| Egocentric speech | Piaget's term for children's non-communicative self-talk, which he saw as a sign of immaturity. |
| Inner speech | Silent, internalized verbal thought — the mature endpoint of private speech. |
| Social speech | Speech addressed to and intended for another person; the developmental origin of private speech. |
| Internalization | The process by which an external, social activity (here, speech) becomes an internal, mental one. |
| Self-regulation | Guiding and controlling one's own attention, behavior, and thinking toward a goal. |
| Executive function | The set of skills — working memory, inhibitory control, cognitive flexibility, planning — that underlie self-control. |
| Self-directed speech | A general term covering both overt private speech and silent inner speech. |
| Self-instructional training | A clinical technique teaching children to guide behavior with deliberate self-statements. |
| Self-talk | The broad, lifespan family of verbalizations directed at the self, of which private and inner speech are the developmental core. |
| Verbal mediation | Using language to guide and organize one's own thought and behavior. |
Frequently Asked Questions
What is private speech?
Private speech is overt, audible speech that children direct at themselves rather than at another person, usually while playing or working on a task. On Vygotsky's account it is a tool for self-regulation that is gradually internalized into silent inner speech (Vygotsky, 1986; Winsler, Fernyhough, & Montero, 2009).
Is private speech the same as inner speech?
No — they are two phases of the same system. Private speech is audible and out loud; inner speech is silent verbal thought. Private speech develops into inner speech as it is internalized over childhood (Winsler & Naglieri, 2003; Alderson-Day & Fernyhough, 2015).
Why do children talk to themselves?
To guide themselves. Private speech helps children plan, focus and sustain attention, pace their work, and monitor and correct their own performance, which is why it increases when a task gets harder (Fernyhough & Fradley, 2005; Diaz & Berk, 1992).
How did Piaget and Vygotsky disagree about it?
Piaget called it egocentric speech and saw it as a sign of immaturity that simply fades. Vygotsky argued it does not disappear but goes inward, becoming inner speech, and that it does the important work of self-guidance. Later evidence has largely favored Vygotsky (Piaget, 1959; Vygotsky, 1986; Berk, 1986).
Is private speech a sign of a problem, such as ADHD?
Generally no — it is a normal and helpful part of development. Children with ADHD do tend to produce more task-irrelevant private speech and to internalize it later, and adults with more ADHD traits report more self-directed speech, but self-talk itself is typical and often useful rather than a deficit (Berk & Potts, 1991; Benfield & Cole, 2026).
Should parents and teachers stop children from talking to themselves?
Usually not. A child muttering through a task is self-guiding, not misbehaving, and suppressing it can remove a support they still rely on; allowing productive private speech is generally the better course (Diaz & Berk, 1992).
References
| 1 | Alderson-Day, B., & Fernyhough, C. (2015). Inner speech: Development, cognitive functions, phenomenology, and neurobiology. Psychological Bulletin, 141(5), 931–965. https://doi.org/10.1037/bul0000021 |
| 2 | Benfield, E., & Cole, G. G. (2026). Self-directed speech and attention deficit hyperactive disorder-like behaviours. British Journal of Psychology. Advance online publication. https://doi.org/10.1111/bjop.70027 |
| 3 | Berk, L. E. (1986). Relationship of elementary school children's private speech to behavioral accompaniment to task, attention, and task performance. Developmental Psychology, 22(5), 671–680. https://doi.org/10.1037/0012-1649.22.5.671 |
| 4 | Berk, L. E., & Potts, M. K. (1991). Development and functional significance of private speech among attention-deficit hyperactivity disordered and normal boys. Journal of Abnormal Child Psychology, 19(3), 357–377. |
| 5 | Bochicchio, V., Keith, K., Montero, I., Scandurra, C., & Winsler, A. (2022). Digital media inhibit self-regulatory private speech use in preschool children: The "digital bubble effect." Cognitive Development, 62, 101180. https://doi.org/10.1016/j.cogdev.2022.101180 |
| 6 | Diaz, R. M., & Berk, L. E. (Eds.). (1992). Private speech: From social interaction to self-regulation. Lawrence Erlbaum. |
| 7 | Fernyhough, C., & Fradley, E. (2005). Private speech on an executive task: Relations with task difficulty and task performance. Cognitive Development, 20(1), 103–120. https://doi.org/10.1016/j.cogdev.2004.11.002 |
| 8 | Latinjak, A. T., Morin, A., Brinthaupt, T. M., Hardy, J., Hatzigeorgiadis, A., Kendall, P. C., Neck, C., Oliver, E. J., Puchalska-Wasyl, M. M., Tovares, A. V., & Winsler, A. (2023). Self-talk: An interdisciplinary review and transdisciplinary model. Review of General Psychology, 27(4), 355–386. https://doi.org/10.1177/10892680231170263 |
| 9 | Piaget, J. (1959). The language and thought of the child (3rd ed.). Routledge & Kegan Paul. (Original work published 1923) |
| 10 | Vygotsky, L. S. (1978). Mind in society: The development of higher psychological processes (M. Cole, V. John-Steiner, S. Scribner, & E. Souberman, Eds.). Harvard University Press. https://doi.org/10.2307/j.ctvjf9vz4 |
| 11 | Vygotsky, L. S. (1986). Thought and language (A. Kozulin, Ed.; E. Hanfmann & G. Vakar, Trans.). MIT Press. (Original work published 1934) |
| 12 | Winsler, A., Fernyhough, C., & Montero, I. (Eds.). (2009). Private speech, executive functioning, and the development of verbal self-regulation. Cambridge University Press. https://doi.org/10.1017/CBO9780511581533 |
| 13 | Winsler, A., & Naglieri, J. (2003). Overt and covert verbal problem-solving strategies: Developmental trends in use, awareness, and relations with task performance in children aged 5 to 17. Child Development, 74(3), 659–678. https://doi.org/10.1111/1467-8624.7403008 |