Memory Development – Arizona Forensic Services, LLC

Snap Shot

The question: How do children’s abilities to take in, hold, organize, and report memories change from infancy through adolescence, and what do those changes mean for a child’s account of an event?

What the research shows: Some learning begins before birth and explicit memory emerges during infancy, but working memory, deliberate strategies, knowledge, language, and the ability to locate an event in time and source all improve gradually through childhood and into adolescence. Younger children report less in free recall and are more affected by suggestive questioning, yet in the few studies able to check, what they reported in response to open-ended questions was generally accurate (closed questions carry more risk), and some kinds of false memory increase rather than decrease with age.

What it does not show: Age alone does not tell a court whether a particular child’s account is accurate or inaccurate. Group differences in how much children recall, or how easily they are led, cannot establish that a specific detail was remembered or supplied.

The law: Every person, including a child, is presumed competent to testify (Fed., Mil., and Ariz. R. Evid. 601; 18 U.S.C. § 3509(c)), and developmental concerns ordinarily go to weight. Children’s out-of-court statements are tested under the hearsay rules and, for testimonial statements, Crawford; expert testimony on memory development is governed by Rule 702, Houser, and in Arizona Salazar-Mercado and Lindsey.

Issues for each side: Prosecutors can show that young children can give accurate accounts when questioned well, but should not present gaps, imprecise dating, or growing detail as irrelevant; defense counsel can show how age interacts with questioning and delay, but should not treat a child’s age as proof of unreliability.

Children testify in child abuse prosecutions, courts-martial, custody disputes, and cases in which they saw a crime against someone else. A child’s account is often the central evidence, and factfinders bring varied assumptions to it: some expect young children to remember little, while others assume a child is too young to have learned the details he or she describes.

Memory development is the study of how the capacities that support remembering change from before birth through adolescence. Adults’ later recall of their own early childhood is treated separately in the paper on Childhood Amnesia, and the effects of suggestive questioning on children in the paper on Suggestibility of Children’s Memory.

This paper summarizes memory in infancy, the growth of working memory, knowledge, strategies, and memory for time, children’s memory for personal events, and the relationship between age, accuracy, and false memory, followed by the limits of the evidence and the law on child competency, children’s out-of-court statements, and expert testimony.

Memory Before Language

Some learning occurs before birth. In a classic study, pregnant women read a particular children’s story aloud repeatedly during the last weeks of pregnancy; after birth, their newborns changed their sucking patterns in ways that favored hearing that story over an unfamiliar one, even when a different woman read it (DeCasper & Spence, 1986). The finding shows that the auditory system can retain the sound pattern of repeated speech before birth. It is not evidence that a fetus or newborn forms memories of events that could later be recalled or described.

During the first year, infants also begin to sort the world into broad kinds. In object-examination studies, infants in the second half of the first year treated animals and vehicles as different categories, even when the toys within a category looked quite different from one another (Mandler & McDonough, 1993).

Explicit memory, for facts and events that can be consciously retrieved, depends on the hippocampus and surrounding cortex, which are largely in place at birth; some hippocampal regions and their connections with prefrontal cortex continue to mature for years (Richmond & Nelson, 2007). In a functional MRI study of awake infants, greater hippocampal activity while an infant viewed a new photograph was associated with later looking behavior indicating memory for that photograph, an effect that appeared from roughly one year of age (Yates et al., 2025).

Language is a separate constraint. In a study of two- to four-year-olds who took part in the same novel event, children’s verbal recall a day later lagged behind both their nonverbal memory, measured by reenactment and photograph recognition, and their general language skill (Simcock & Hayne, 2003). A young child who cannot describe an event may still retain some memory of it; the converse is also true, in that a child’s later words may reflect language and information acquired after the event.

Working Memory

Working memory refers to the limited capacity used to keep information active, and to work with it, for the few seconds a task requires. The model proposed by Baddeley and Hitch (1974) described a central executive that directs attention and two storage components, a phonological loop for verbal and sound-based material and a visuospatial sketchpad for visual and spatial material. Baddeley (2000) later added an episodic buffer, a limited-capacity store that binds information from the other components and from long-term memory into integrated episodes. A child’s ability to assemble who, what, where, and when into one coherent event depends on this binding as well as on storage.

In a study of children from four to fifteen years old, performance on measures of each component rose in broadly similar, roughly linear fashion with age; from age six onward the data fit a three-part structure corresponding to the model, and each part continued to expand in capacity through the school years into adolescence (Gathercole et al., 2004). Younger children also use working memory differently. Spontaneous verbal rehearsal, silently repeating material to keep it active, was uncommon among five-year-olds and common among ten-year-olds in an early study (Flavell et al., 1966), and reviews place the routine use of rehearsal at about seven years (Gathercole, 1998). Older children rehearse several items together rather than one at a time, a pattern associated with better recall (Ornstein et al., 1975).

In practice, a long or compound question can exceed a young child’s working-memory capacity, so that the child answers only part of it; the answer then says more about the question than about the child’s memory.

Knowledge, Strategies, and Metamemory

Much of the improvement in memory across childhood reflects growth in what children know, how they go about remembering, and what they understand about their own memory (Schneider & Ornstein, 2019). Knowledge about a domain helps a child notice what matters, organize it, and retrieve it later, and when material is equally familiar to younger and older children, age differences in memory are often reduced. Deliberate strategies such as rehearsal, grouping items by category, and elaboration appear gradually, are used inconsistently at first, and become more spontaneous and effective in middle childhood and adolescence. Metamemory, a child’s knowledge about how memory works and how well he or she remembers, improves in parallel, and it bears on whether a child can say accurately that he or she does not know or does not remember.

Episodic memory, memory for specific events with their context, improves substantially in middle childhood. A review of behavioral and imaging studies linked this improvement to the ability to bind the details of an event together and to monitor and evaluate memories, processes associated with continuing maturation of the hippocampus and prefrontal cortex (Ghetti & Bunge, 2012). Source monitoring, identifying where a remembered detail came from, follows a similar course.

Memory for time develops especially slowly. A recent review proposed that young children’s memory for when events occurred is initially local and tied to individual events, and that the ability to place events within broader temporal patterns, such as the order of repeated episodes or the calendar, develops through later childhood and adolescence with growing interaction between the hippocampus and frontoparietal cortex (Friend et al., 2026). The framework is a synthesis, but it fits the common observation that children who can describe what happened often cannot say when, how many times, or in what order.

Memory for Personal Events

Children begin to talk about their own past experiences in the third year of life. In an early study of conversations between mothers and children not yet three, the children could describe events from months earlier, although their accounts were brief and depended heavily on the adult’s questions (Fivush et al., 1987). Children’s ability to give an independent, organized narrative grows with language, with a sense of themselves as the person to whom events happen (Howe & Courage, 1997), and with experience in talking about the past.

How adults talk with children about past events matters. Children whose mothers reminisce in an elaborative way, asking open questions and adding detail, tend to develop richer and more organized personal memories (Fivush et al., 2006). That benefit has a forensic counterpart. In an experiment with 141 children aged four to seven and their mothers, maternal elaboration increased accurate recall in the mother-child conversation when the mother had accurate information about the event, but among younger children it also increased inaccurate details in that conversation, and it was associated with fewer accurate details when children were later interviewed alone by an unfamiliar adult, whether the mothers had been given accurate or misleading information (Lawson et al., 2025). Conversations at home can therefore both strengthen and reshape a child’s account.

Stressful personal events show the same developmental pattern. Children injured seriously enough to need emergency treatment were interviewed repeatedly over up to two years; those injured before about eighteen months showed little long-term verbal recall, while most children who already had narrative skills at the time of injury gave good accounts two years later, although even their recall contained errors (Peterson & Rideout, 1998). A review concluded that children can retain stressful preschool experiences over long periods but that accounts of the earliest events are sparse and more error-prone (Peterson, 2012). Whether such memories persist into adulthood is addressed in the paper on Childhood Amnesia; in brief, the average adult’s earliest memory dates to about three to three and a half years, and very few reliable memories date from before age two.

Age, Accuracy, and False Memory

Younger children generally report less information than older children in free recall, but in the few studies able to check, what they reported in response to open-ended invitations was generally accurate; many of those studies used staged, non-abusive events, and closed questions carry more risk. Field research on the NICHD Investigative Interview Protocol found that open-ended prompts elicited more information, and more accurate information, than focused or suggestive questions from children of all ages studied, including preschool children (Lamb et al., 2007). The weakness of young children’s memory lies more in completeness and in vulnerability to the form of questioning than in the accuracy of freely given information. Preschool children are, on average, more affected by leading questions, repeated suggestive interviews, and stereotypes than older children and adults, a subject addressed in the paper on Suggestibility of Children’s Memory.

The developmental picture is not uniformly one in which younger means less reliable. Research on spontaneous false memories, errors that arise from a person’s own understanding of the meaning of an experience rather than from outside suggestion, has found that these errors often increase with age from early childhood into adulthood, because older children and adults connect related information more readily (Brainerd et al., 2008). A recent review proposed a framework for predicting when each age trend will appear, distinguishing internally generated distortions, which tend to increase with age, from distortions introduced by external suggestion, which tend to decrease with age (Rosendaul et al., 2023). No single age gradient describes all memory errors.

Limits of the Evidence

Most research on memory development uses staged activities, laboratory tasks, or medical procedures, which differ from the experiences at issue in many cases in meaning, repetition, the child’s relationship to the people involved, and delay. Samples are often small, drawn from particular communities, and not representative of maltreated children, children with developmental disabilities, or children who are not native speakers of the language of the interview.

Age is an imperfect proxy for development. Children of the same age differ widely in language, working memory, knowledge, and executive function, and group averages conceal that variation. Neuroscience findings describe group-level processes and cannot evaluate a particular child’s account, and findings about children’s accuracy are partly findings about the questioning methods used.

Questions to Ask About This Research

When the finding from Lamb et al. (2007) is offered to show that young children give accurate information to open-ended questions, counsel should ask whether the conclusion follows for this child: the result describes interviews that followed the NICHD Protocol, so the answer depends on how this child’s interview was actually conducted and how many of its questions were open-ended. When Lawson et al. (2025) is cited for the proposition that family conversations distort children’s memory, counsel should ask what exactly was measured: the study involved children aged four to seven, a staged event the mother had not witnessed, and an experimental manipulation of what mothers were told, and it found both benefits and costs of elaboration. When Peterson and Rideout (1998) is used to argue that an event at a particular age could or could not be remembered, counsel should ask who was studied and how much evidence the finding provides about one child, since the study followed small groups of injured children and found wide individual differences. When developmental reversals are raised (Brainerd et al., 2008), counsel should ask whether the errors at issue are internally generated or suggestion-induced. These questions are explained in “Reading Research Claims: A Guide for Attorneys” on this site.

Memory Development and the Law

Federal and Military Standards

The law no longer treats young children as presumptively incompetent. In Wheeler v. United States (1895), the Supreme Court allowed a five-year-old to testify, holding that competency depends on the child’s capacity and intelligence and understanding of the duty to tell the truth, a question for the trial judge who sees and hears the child. Federal Rule of Evidence 601 now provides that every person is competent to be a witness unless the rules provide otherwise. In federal prosecutions, 18 U.S.C. § 3509(c) presumes a child competent, permits a competency examination only on written motion, an offer of proof, and a finding of compelling reasons, which age alone cannot supply, and requires that questions at the examination be appropriate to the child’s developmental level and not concern the issues at trial. In Kentucky v. Stincer (1987), the Court held that excluding a defendant from a competency hearing for two child witnesses did not violate the Confrontation Clause or due process where the children later testified subject to full cross-examination. Research on competency questioning is consistent with this approach; in a study of child witnesses in court, judges virtually never found children incompetent, and abstract questions asking children to define truth and lies underestimated what children understood (Evans & Lyon, 2012). Military Rule of Evidence 601 contains the same presumption of competency.

Children’s out-of-court statements raise both hearsay and confrontation questions. Idaho v. Wright (1990) held that a young child’s statements to a pediatrician lacked the particularized guarantees of trustworthiness then required, and it identified the circumstances of questioning as relevant to reliability while declining to mandate any interview procedure. Wright predates Crawford v. Washington (2004), which bars a non-testifying declarant’s testimonial statements unless the declarant is unavailable and the defendant had a prior opportunity for cross-examination, and Whorton v. Bockting (2007) confirmed that the Confrontation Clause does not govern nontestimonial hearsay. Ohio v. Clark (2015) concluded that statements a three-year-old made to preschool teachers about his injuries were not testimonial, and the Court observed that statements by very young children will rarely, if ever, implicate the Confrontation Clause.

Expert testimony on memory development is governed by Federal Rule of Evidence 702, as amended December 1, 2023, which requires the proponent to show that it is more likely than not that the testimony rests on sufficient facts or data, reflects reliable principles and methods, and reflects a reliable application of them to the case. Daubert v. Merrell Dow Pharmaceuticals, Inc. (1993) makes the trial judge a gatekeeper, and Kumho Tire Co. v. Carmichael (1999) extends that obligation to all expert testimony, including non-scientific technical or other specialized knowledge. In courts-martial, Military Rule of Evidence 702 tracks the federal rule; the 2023 amendment took effect in the military rule in 2025 through Military Rule of Evidence 1102 (Joint Service Committee on Military Justice, 2025; practitioners should confirm current text), and United States v. Houser (1993) sets out six factors governing admissibility.

Arizona

Arizona Rule of Evidence 601 and A.R.S. § 13-4061 provide that every person is competent to be a witness, and competency is a preliminary question for the court. In State v. Robinson (1987), the Arizona Supreme Court held a statutory child-hearsay exception, A.R.S. § 13-1416, unconstitutional as conflicting with the court’s rules of evidence, so children’s out-of-court statements are evaluated under the ordinary hearsay rules, including the residual exception in Rule 807, together with Crawford. Arizona Rule of Evidence 702 adopted the Daubert standard effective January 1, 2012, and was amended effective January 1, 2024, to track the 2023 federal amendment (Ariz. Sup. Ct. Order R-23-0004). Under State v. Salazar-Mercado (2014), an expert may give general, educational testimony about memory development without applying it to the facts, if the testimony satisfies Rule 702 and Rule 403. Under State v. Lindsey (1986) and State v. Moran (1986), no expert may opine, directly or indirectly, on whether a particular witness is truthful or accurate.

Special Issues in Legal Practice

The principles described above apply with equal force to every party in a legal proceeding. The science operates the same way regardless of who is asking the questions, and the research summarized here does not by itself favor either side. What differs between the parties is not the science but the vantage point — the particular places where these issues tend to surface, and the particular errors each party is best positioned to guard against. The two summaries below identify those recurring issues. They are offered for orientation, not as litigation strategy; in every case the controlling question is what the evidence in that case will, and will not, support, and the expert’s role is to inform the trier of fact rather than to advocate for either side.

Special Issues for Prosecutors

The research supports several propositions prosecutors can legitimately present. Children, including preschool children, can give accurate accounts of personal experiences, and information they provided in response to open-ended invitations was generally accurate in the few studies able to check. Young children can retain stressful events over long periods. A child who cannot give a date, a count of incidents, or a precise sequence may still accurately remember what happened, because memory for time develops later than memory for events, and a child’s struggle with a compound or abstract question may reflect working-memory and language demands rather than an absence of memory. Some kinds of spontaneous false memory increase with age, while errors from external suggestion tend to decrease with age, so no single age gradient describes all memory errors, and age alone is not a reason either to credit or to discount an account. Prosecutors are well positioned to ensure that interviews are recorded, early, and open-ended, and that investigators document what the child was told and by whom.

The research also counsels caution. Young children report less in free recall and are more affected by leading, repeated, and suggestive questioning than older children, so the value of an account depends heavily on how it was obtained. Elaborative conversations with parents and others can add inaccurate detail as well as accurate detail, particularly for younger children. Accounts of events from the first two or three years of life are sparse and more error-prone. Testimony that treats added detail over successive conversations, or a child’s confidence, as corroboration goes beyond what the research shows, and an expert may not vouch for a particular child.

Special Issues for Defense

The research supports several propositions defense counsel can legitimately present. Working memory, knowledge, strategy use, source monitoring, and memory for time all develop gradually, and younger children are, on average, more susceptible to leading and repeated questioning and to the influence of adults’ expectations. Conversations with parents and others before a formal interview can shape a child’s report in both directions. A young child’s verbal account may reflect language and information acquired after the event. Expert testimony explaining these principles, combined with evidence of how and when a child was questioned, is a legitimate way to help the factfinder evaluate an account.

The research also counsels caution about the limits that apply to the defense. Age does not make a child incompetent or an account unreliable, and children’s free recall in good interviews was generally accurate in the few studies able to check, mostly of staged, non-abusive events. Difficulty with dates, frequency, and sequence is expected at younger ages and does not by itself indicate that an event did not occur. Developmental findings describe groups and cannot show that a particular detail was suggested or that a particular child’s memory is false, and arguments that rely on a child’s age alone, without evidence about the questioning, risk overstating the research.

This paper is for educational purposes only and is not legal advice. The author is a psychologist, not an attorney; summaries of law are general and must be verified against current authority or with a licensed attorney.

References

Baddeley, A. (2000). The episodic buffer: A new component of working memory? Trends in Cognitive Sciences, 4(11), 417–423. https://doi.org/10.1016/S1364-6613(00)01538-2

Baddeley, A. D., & Hitch, G. (1974). Working memory. In G. H. Bower (Ed.), The psychology of learning and motivation (Vol. 8, pp. 47–89). Academic Press. https://doi.org/10.1016/S0079-7421(08)60452-1

Brainerd, C. J., Reyna, V. F., & Ceci, S. J. (2008). Developmental reversals in false memory: A review of data and theory. Psychological Bulletin, 134(3), 343–382. https://doi.org/10.1037/0033-2909.134.3.343

DeCasper, A. J., & Spence, M. J. (1986). Prenatal maternal speech influences newborns’ perception of speech sounds. Infant Behavior and Development, 9(2), 133–150. https://doi.org/10.1016/0163-6383(86)90025-1

Evans, A. D., & Lyon, T. D. (2012). Assessing children’s competency to take the oath in court: The influence of question type on children’s accuracy. Law and Human Behavior, 36(3), 195–205. https://doi.org/10.1037/h0093957

Fivush, R., Gray, J. T., & Fromhoff, F. A. (1987). Two-year-olds talk about the past. Cognitive Development, 2(4), 393–409. https://doi.org/10.1016/S0885-2014(87)80015-1

Fivush, R., Haden, C. A., & Reese, E. (2006). Elaborating on elaborations: Role of maternal reminiscing style in cognitive and socioemotional development. Child Development, 77(6), 1568–1588. https://doi.org/10.1111/j.1467-8624.2006.00960.x

Flavell, J. H., Beach, D. R., & Chinsky, J. M. (1966). Spontaneous verbal rehearsal in a memory task as a function of age. Child Development, 37(2), 283–299. https://doi.org/10.2307/1126804

Friend, O. W., Pathman, T., & Preston, A. R. (2026). Increasing representational capacity in the hippocampal-frontoparietal system underlies hierarchical development of temporal memory. Developmental Cognitive Neuroscience, 79, Article 101713. https://doi.org/10.1016/j.dcn.2026.101713

Gathercole, S. E. (1998). The development of memory. Journal of Child Psychology and Psychiatry, 39(1), 3–27. https://doi.org/10.1111/1469-7610.00301

Gathercole, S. E., Pickering, S. J., Ambridge, B., & Wearing, H. (2004). The structure of working memory from 4 to 15 years of age. Developmental Psychology, 40(2), 177–190. https://doi.org/10.1037/0012-1649.40.2.177

Ghetti, S., & Bunge, S. A. (2012). Neural changes underlying the development of episodic memory during middle childhood. Developmental Cognitive Neuroscience, 2(4), 381–395. https://doi.org/10.1016/j.dcn.2012.05.002

Howe, M. L., & Courage, M. L. (1997). The emergence and early development of autobiographical memory. Psychological Review, 104(3), 499–523. https://doi.org/10.1037/0033-295X.104.3.499

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Lamb, M. E., Orbach, Y., Hershkowitz, I., Esplin, P. W., & Horowitz, D. (2007). A structured forensic interview protocol improves the quality and informativeness of investigative interviews with children: A review of research using the NICHD Investigative Interview Protocol. Child Abuse & Neglect, 31(11–12), 1201–1231. https://doi.org/10.1016/j.chiabu.2007.03.021

Lawson, M., Rodriguez Steen, L., London, K., Holland, T., Gorelik, K., & Ferguson, S. (2025). Maternal elaboration and children’s episodic memory accuracy: A double-edged sword? Developmental Psychology, 61(4), 726–738. https://doi.org/10.1037/dev0001924

Mandler, J. M., & McDonough, L. (1993). Concept formation in infancy. Cognitive Development, 8(3), 291–318. https://doi.org/10.1016/S0885-2014(93)80003-C

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Peterson, C. (2012). Children’s autobiographical memories across the years: Forensic implications of childhood amnesia and eyewitness memory for stressful events. Developmental Review, 32(3), 287–306. https://doi.org/10.1016/j.dr.2012.06.002

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Rosendaul, B. J., Su, I. A., & Ceci, S. J. (2023). Normative developmental vs. reverse developmental trends in memory distortion: A framework to investigate the impact of internal and external influences on memory and their relevance to legal decisions. Frontiers in Psychology, 14, Article 1232753. https://doi.org/10.3389/fpsyg.2023.1232753

Schneider, W., & Ornstein, P. A. (2019). Determinants of memory development in childhood and adolescence. International Journal of Psychology, 54(3), 307–315. https://doi.org/10.1002/ijop.12503

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Legal Authorities

Crawford v. Washington, 541 U.S. 36 (2004).

Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993).

Idaho v. Wright, 497 U.S. 805 (1990).

Kentucky v. Stincer, 482 U.S. 730 (1987).

Kumho Tire Co. v. Carmichael, 526 U.S. 137 (1999).

Ohio v. Clark, 576 U.S. 237 (2015).

State v. Lindsey, 149 Ariz. 472, 720 P.2d 73 (1986).

State v. Moran, 151 Ariz. 378, 728 P.2d 248 (1986).

State v. Robinson, 153 Ariz. 191, 735 P.2d 801 (1987).

State v. Salazar-Mercado, 234 Ariz. 590, 325 P.3d 996 (2014).

United States v. Houser, 36 M.J. 392 (C.M.A. 1993).

Wheeler v. United States, 159 U.S. 523 (1895).

Whorton v. Bockting, 549 U.S. 406 (2007).

U.S. Const. amend. VI.

18 U.S.C. § 3509(c).

Ariz. Rev. Stat. Ann. § 13-1416 (held unconstitutional in State v. Robinson).

Ariz. Rev. Stat. Ann. § 13-4061.

Fed. R. Evid. 601.

Fed. R. Evid. 702.

Ariz. R. Evid. 601.

Ariz. R. Evid. 702.

Ariz. R. Evid. 807.

Ariz. Sup. Ct. Order R-23-0004 (amending Ariz. R. Evid. 702, effective Jan. 1, 2024).

Mil. R. Evid. 601.

Mil. R. Evid. 702.

Mil. R. Evid. 1102.

Related topics from Arizona Forensic Services: Child Abuse Allegations · Courts-Martial