The Reminiscence Bump – Arizona Forensic Services, LLC

Snap Shot

The question: Why do adults past midlife retrieve an outsized share of their memories from roughly ages 10 to 30, and what does that pattern mean for testimony about events from the teens and twenties given years or decades later?

What the research shows: The reminiscence bump has been found consistently across many methods, ages, and cultures, although its location and size vary with the method used. Its location depends on how memories are cued, earlier for word-cued memories and later for most important memories. It is explained by a combination of encoding, identity, life-story, and cultural life-script processes, and it is generally stronger for positive than for negative events, although recent studies find a bump for negative memories as well.

What it does not show: The bump is a count of how often memories are retrieved from each period of life; it says nothing directly about their accuracy. It does not show that memories from adolescence are more likely to be true, that a traumatic event from those years must be vividly remembered, or that memories from youth are generally unreliable, and it does not establish when a remembered event occurred.

The law: Personal knowledge (Rule 602), Rule 702, and Houser govern testimony about long-past events; in Arizona, Rule 702, Chapple, and Nordstrom govern, and under Lindsey no expert may say whether a particular memory is accurate.

Issues for each side: Prosecutors can explain why substantial memory from adolescence may survive decades, without treating abundance or vividness as proof of accuracy; defense counsel can show that fluency is not accuracy and that remote events are often misdated, without asserting that memories of youth are generally false.

If older adults recall events from across their lives and estimate their age at each one, the resulting memories cluster unevenly across the decades. Few come from early childhood, many come from the recent past, and a conspicuous surplus comes from adolescence and early adulthood. That surplus is the reminiscence bump. The bump has been found consistently across many methods and cultures, although its location and size vary with the method used, and it has a direct bearing on cases in which an adult describes events from his or her teens or twenties long after they occurred.

The question in such cases is often framed as whether a person could still remember an event after twenty or forty years. The research on the bump helps answer part of that question: memories from this period of life remain unusually accessible across the rest of the lifespan. It does not answer the other part, whether the details of a particular memory are accurate, and it does not answer when a remembered event happened. Those distinctions, between how much is remembered, how accurately, and how well it is dated, are the focus of this paper.

This paper describes the lifespan distribution of autobiographical memory, how the location of the bump depends on the way memories are elicited, the competing explanations for the bump, its relationship to emotional valence, and what it means for older adults recalling events from youth, including the dating of remote events. It then reviews the limits of the evidence and the governing law. How memory develops during adolescence itself, and how adolescents perform as witnesses, is addressed in the companion paper, Memory Across Puberty and the Reminiscence Bump.

The Lifespan Distribution of Autobiographical Memory

In an early analysis of studies in which older adults recalled personal memories in response to cue words, Rubin, Wetzler, and Nebes (1986) described a retrieval curve with three components. Childhood amnesia accounts for the scarcity of memories from the first years of life; 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. A retention component produces the many memories from the most recent years. Between them, memories from roughly ages 10 to 30 exceed what ordinary forgetting would predict.

The pattern extends beyond personal events. Rubin, Rahhal, and Poon (1998) reviewed evidence that for older adults the period from 10 to 30 supplies the most autobiographical memories, the most vivid and the most important memories, and the favorite books, films, and music, and that older adults answered factual questions about events from that period more accurately. The pattern has limits, however. In a 2024 study of 1,012 Germans aged 30 to 80, knowledge of public events from the past six decades did not peak for events experienced in adolescence or early adulthood; scores were lower for events before participants’ birth and roughly stable from about ages 5 to 10 onward, a result the authors read as evidence against extending the bump to factual knowledge (Achaa-Amankwaa et al., 2024).

The bump appears in many populations. In a large online study of participants in the United States and the Netherlands, the bump appeared in every age group from 11 to 70, and neither age nor education changed its location; its peak came somewhat earlier for women than for men, a difference discussed in the companion paper (Janssen et al., 2005). Groups from Japan, China, Bangladesh, England, and the United States produced similar lifespan retrieval curves, although the content of the memories reflected cultural differences in self-focus (Conway et al., 2005). A systematic review reported the bump across a wide range of designs and samples and discussed how its location and size vary with method (Munawar et al., 2018).

How the Cue Shapes the Bump

Researchers elicit autobiographical memories in two main ways: by asking people to recall a memory in response to a cue word, such as “car” or “letter,” or by asking for their most important memories or the events that shaped their lives. In a review of studies using each approach, Koppel and Berntsen (2015) found that the bump’s location depended on the method: mean bump ranges fell between about 9 and 22 years for word-cued memories and between about 15 and 28 years for important memories. Koppel and Rubin (2016) emphasized the role of retrieval cues in guiding recall and argued that theories of the bump must account for the effect of the retrieval task.

Social context can also matter. In a study in which older adults described three memories to interviewers of different ages, the interviewer’s age, particularly when the interviewer was a child, affected where the bump fell (Sakata, 2024). The finding is from a single study, but it fits the broader point that the memories a person produces depend in part on what is asked, by whom, and why. A forensic interview, a therapy session, a conversation with family, and testimony are different retrieval contexts, and the research suggests that the context may influence which memories come to mind.

Why the Bump Occurs

Researchers agree that the bump is real and disagree about why it occurs; most now conclude that more than one process contributes.

One family of explanations emphasizes encoding. Adolescence and early adulthood bring many first experiences and transitions, and novel, distinctive events may be encoded more richly and later rehearsed. A test of this idea comes from older Hispanic adults who immigrated to the United States at ages ranging from about 20 to 35: instead of the usual bump, their life stories showed an increase in memories corresponding to their ages at immigration (Schrauf & Rubin, 2001). The study involved ten participants, but it suggests that a major life transition can relocate the period of heightened memory.

A second family of explanations emphasizes identity. The self-memory system model holds that autobiographical memories are organized around a person’s goals and self-conceptions, and that memories tied to the formation of an enduring identity remain especially accessible (Conway & Pleydell-Pearce, 2000). In a study in which participants generated “I am” statements and then recalled memories related to each, the memories clustered around the time each self-image emerged (Rathbone et al., 2008). Five studies collecting about 10,000 memories reported findings consistent with this identity-formation account (Curci et al., 2024). A related life-story account predicted, and found in 3,541 life events reported by adults aged 50 to 90, that the bump was limited to positive events over which people felt they had control and that they saw as influential in their later lives (Glück & Bluck, 2007).

A third explanation emphasizes culture. Berntsen and Rubin (2004) presented evidence for cultural life scripts, shared expectations about when major life events should occur, and found that transitional events expected between ages 15 and 30 were predominantly positive and that only positive events increased over that age range when people estimated a hypothetical person’s life. On this account, the script guides retrieval, so events it anticipates are recalled more readily. No single explanation accounts for all the data. In one large study, the bump remained after differences in the novelty, emotionality, valence, and importance of events were taken into account (Janssen & Murre, 2008).

For legal purposes, the competing explanations share an implication. Each describes why memories from this period are more often retrieved, not why they would be more accurate. The life-script account in particular proposes that recall of youth is guided partly by cultural expectations about what typically happens at those ages; its supporting evidence comes largely from studies in which people described a typical or hypothetical life, and it does not show that any particular memory was reshaped.

Positive and Negative Memories

The relationship between the bump and emotional valence is important and easily misread. In a study of 1,241 adults aged 20 to 93 who reported their age at the time of their happiest, saddest, most traumatic, and most important memories, older respondents showed a clear bump in their twenties for the happiest and most important memories, while the saddest and most traumatic memories showed a steadily declining distribution with more memories from recent years (Berntsen & Rubin, 2002). That finding, together with the life-script research, led to the view that the bump is largely a phenomenon of positive memories.

More recent research qualifies that view. Across five studies of public, private, and music-related memories, one comparing Chinese and U.S. participants, positive memories tended to be older than negative ones, but a bump appeared for both positive and negative memories; for public events the peak for positive memories fell before about age 15 and the peak for negative memories between about 20 and 40, while for private and music-related memories no difference in location was found (Curci et al., 2024). The research therefore does not support either of two opposing claims sometimes made in court: that a distressing event from adolescence must be especially well remembered because it falls in the bump, or that negative events from that period are not subject to the bump at all. How distressing and traumatic events are remembered is addressed in Emotion, Stress, Trauma, and Memory.

Older Adults, Long Delays, and Dating

Cases involving historical allegations, events reported years or decades after they occurred, often depend on an adult’s recollection of adolescence. Limitation periods for sexual offenses against minors have been extended or eliminated in many jurisdictions, so such cases can turn on memories that are decades old. The bump research is relevant in two ways. It indicates that memories of the teens and twenties generally remain accessible far longer than an assumption of steady forgetting would suggest. It also shows that accessibility is a statement about the quantity and ease of retrieval, not about the accuracy of details, which remain subject to the reconstruction, schema-based inference, and post-event influence described in other papers in this series.

The bump persists even when memory is impaired. In a 2022 study, older adults with Alzheimer’s disease produced episodic memories predominantly from ages 6 to 30, with a steep drop in memories of events after age 30 (Berntsen et al., 2022). The finding illustrates how durable the accessibility of memories from youth can be; it does not show that the details of those memories are accurate, and the effects of aging on memory more generally are addressed in Aging and Memory.

Knowing that an event happened is different from knowing when it happened. A review of laboratory and autobiographical research on memory for the time of past events concluded that memory contains no single, natural code for when an event happened; people instead construct their sense of when it occurred, drawing on information such as how long ago it seems, how it was ordered relative to other events, and where it fits in the patterns of their lives (Friedman, 1993). In practice, that often means reasoning from landmarks such as where a person lived, what grade he or she was in, or what else was happening at the time. In a study of how people date events, remote news events were often dated as more recent than they were, a forward telescoping error, and dates given in absolute terms were more accurate than those given in relative terms such as “three years ago” (Janssen et al., 2006). An adult’s anchoring of an adolescent event to a school year, a residence, or a holiday is the kind of reconstruction the research describes, and its accuracy depends on how well those landmarks are themselves remembered and documented. Dating errors are addressed further in The Telescoping Effect.

Limits of the Evidence

Most bump research asks people to retrieve memories and then estimate their age at the time; it counts memories and does not check their accuracy, so it can describe how memories are distributed across a life but not how faithful they are. Many studies use convenience or online samples, and the location of the bump varies with the retrieval method, the type of memory requested, the culture, and, in at least one study, the interviewer. Age at encoding is itself estimated by participants and is subject to dating error. The research on negative and traumatic memories is mixed and depends on how those memories are defined and elicited. And the research describes groups: it cannot establish whether a particular adult’s memory of adolescence is accurate, complete, or correctly dated.

Questions to Ask About This Research

When an expert relies on the bump (Rubin et al., 1986; Munawar et al., 2018) to account for detailed recall of teenage events decades later, counsel should ask what exactly was counted: these studies tallied how many memories participants dated to each age, and did not test whether the memories were correct. When the bump is offered to support or to question a memory of a distressing event, counsel should ask which memories were studied, because Berntsen and Rubin (2002) found the bump for happy and important memories but not for the saddest and most traumatic, while Curci et al. (2024) found a bump for both positive and negative memories, with differences that depended on the type of event. When an expert relies on a specific age range for the bump, counsel should ask how the memories were cued, because Koppel and Berntsen (2015) found that word-cued and important memories peak at different ages. When the bump is used to suggest that a long-ago event was correctly dated, counsel should ask whether the conclusion follows from the design, because dating research (Friedman, 1993; Janssen et al., 2006) shows that remote events are often misdated. Finally, counsel should ask whether the group pattern applies to this person, because older adults who immigrated in adulthood showed heightened recall around their ages at immigration rather than the usual peak (Schrauf & Rubin, 2001). These questions are explained in “Reading Research Claims: A Guide for Attorneys” on this site.

The Reminiscence Bump and the Law

Federal and Military Standards

A witness may testify to a matter only if evidence is introduced sufficient to support a finding that the witness has personal knowledge of it, and the witness’s own testimony may supply that evidence (Fed. R. Evid. 602; Mil. R. Evid. 602). The age of a memory therefore ordinarily goes to weight, tested through cross-examination, corroborating or contradicting evidence, and, where admissible, expert testimony. Expert testimony on autobiographical memory 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 admissibility factors, including the expert’s qualifications, the relevance and reliability of the testimony, and its probative value. General testimony about the lifespan distribution of memory and the dating of remote events fits within these standards; testimony that the bump shows a particular memory is accurate, or inaccurate, does not.

Arizona

Arizona Rule of Evidence 602 contains the same personal-knowledge requirement. 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). State v. Chapple (1983) is Arizona’s leading case on expert testimony about memory, holding that exclusion of eyewitness memory testimony was an abuse of discretion on its facts, and State v. Nordstrom (2001) confirmed that admission otherwise remains within the trial court’s discretion. Under State v. Lindsey (1986) and State v. Moran (1986), an expert may describe general patterns but may not opine, directly or by implication, on whether a particular witness is truthful or whether a particular memory is accurate; those limits apply to testimony offered by either side.

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. Memories from adolescence and early adulthood remain unusually accessible across the lifespan, so the passage of decades does not by itself imply that an adult has lost memory of events from those years. The bump is robust across methods and cultures, and recent research finds it for negative as well as positive memories. Prosecutors are well positioned to strengthen a long-delayed account by identifying independent landmarks, such as school records, residences, and contemporaneous communications, that anchor when and where events occurred.

The research also counsels caution. The bump concerns the number and accessibility of memories, not their accuracy, and testimony that a memory of youth is accurate because it is recalled with confidence and rich detail goes beyond the research. Remote events are often misdated, and charging periods tied to a witness’s estimate of age or grade may need independent support. Testimony that a distressing event from adolescence must be well remembered because it falls within the bump overstates research in which findings on negative memories are mixed.

Special Issues for Defense

The research supports several propositions defense counsel can legitimately present. The ease and richness with which an adult recalls youthful events is an expected feature of how autobiographical memory is distributed across a life and is not, by itself, an index of accuracy. Some accounts propose that recall of youth is guided partly by cultural life scripts and the person’s life story; the supporting evidence comes largely from studies in which people described typical or hypothetical lives, and it does not show that any particular memory was reshaped. People rarely store the date of an event and instead infer it, and remote events are often placed too recently. Expert testimony explaining these principles, combined with evidence about how and when a memory was first reported and dated, can help the factfinder evaluate a long-delayed account.

The research also counsels caution about the limits that apply to the defense. The bump does not show that memories of adolescence are generally false or fabricated, and it supports the opposite inference about their survival: substantial memory from those years is expected decades later. The research does not support the claim that negative or traumatic events from youth are not remembered. Dating error concerns when an event happened, not whether it happened. An expert may not tell the factfinder that a particular memory is inaccurate.

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

Achaa-Amankwaa, P., Steger, D., Wilhelm, O., & Schroeders, U. (2024). Public events knowledge in an age-heterogeneous sample: Reminiscence bump or bummer? Psychology and Aging, 39(1), 72–87. https://doi.org/10.1037/pag0000786

Berntsen, D., Kirk, M., & Kopelman, M. D. (2022). Autobiographical memory loss in Alzheimer’s disease: The role of the reminiscence bump. Cortex, 150, 137–148. https://doi.org/10.1016/j.cortex.2022.02.008

Berntsen, D., & Rubin, D. C. (2002). Emotionally charged autobiographical memories across the life span: The recall of happy, sad, traumatic, and involuntary memories. Psychology and Aging, 17(4), 636–652. https://doi.org/10.1037/0882-7974.17.4.636

Berntsen, D., & Rubin, D. C. (2004). Cultural life scripts structure recall from autobiographical memory. Memory & Cognition, 32(3), 427–442. https://doi.org/10.3758/BF03195836

Conway, M. A., & Pleydell-Pearce, C. W. (2000). The construction of autobiographical memories in the self-memory system. Psychological Review, 107(2), 261–288. https://doi.org/10.1037/0033-295X.107.2.261

Conway, M. A., Wang, Q., Hanyu, K., & Haque, S. (2005). A cross-cultural investigation of autobiographical memory: On the universality and cultural variation of the reminiscence bump. Journal of Cross-Cultural Psychology, 36(6), 739–749. https://doi.org/10.1177/0022022105280512

Curci, A., Battista, F., Lanciano, T., d’Ovidio, F. D., & Conway, M. A. (2024). The reminiscence bump and the self: Evidence from five studies on positive and negative memories. Memory, 32(6), 757–775. https://doi.org/10.1080/09658211.2024.2325522

Friedman, W. J. (1993). Memory for the time of past events. Psychological Bulletin, 113(1), 44–66. https://doi.org/10.1037/0033-2909.113.1.44

Glück, J., & Bluck, S. (2007). Looking back across the life span: A life story account of the reminiscence bump. Memory & Cognition, 35(8), 1928–1939. https://doi.org/10.3758/BF03192926

Janssen, S. M. J., Chessa, A. G., & Murre, J. M. J. (2005). The reminiscence bump in autobiographical memory: Effects of age, gender, education, and culture. Memory, 13(6), 658–668. https://doi.org/10.1080/09658210444000322

Janssen, S. M. J., Chessa, A. G., & Murre, J. M. J. (2006). Memory for time: How people date events. Memory & Cognition, 34(1), 138–147. https://doi.org/10.3758/BF03193393

Janssen, S. M. J., & Murre, J. M. J. (2008). Reminiscence bump in autobiographical memory: Unexplained by novelty, emotionality, valence, or importance of personal events. Quarterly Journal of Experimental Psychology, 61(12), 1847–1860. https://doi.org/10.1080/17470210701774242

Joint Service Committee on Military Justice. (2025). Amendments to the Military Rules of Evidence since 1984 (G. E. Maggs, Ed.; 2025 ed.). https://jsc.defense.gov/Portals/99/MRE%20Amendments%202025.pdf

Koppel, J., & Berntsen, D. (2015). The peaks of life: The differential temporal locations of the reminiscence bump across disparate cueing methods. Journal of Applied Research in Memory and Cognition, 4(1), 66–80. https://doi.org/10.1016/j.jarmac.2014.11.004

Koppel, J., & Rubin, D. C. (2016). Recent advances in understanding the reminiscence bump: The importance of cues in guiding recall from autobiographical memory. Current Directions in Psychological Science, 25(2), 135–140. https://doi.org/10.1177/0963721416631955

Munawar, K., Kuhn, S. K., & Haque, S. (2018). Understanding the reminiscence bump: A systematic review. PLOS ONE, 13(12), Article e0208595. https://doi.org/10.1371/journal.pone.0208595

Rathbone, C. J., Moulin, C. J. A., & Conway, M. A. (2008). Self-centered memories: The reminiscence bump and the self. Memory & Cognition, 36(8), 1403–1414. https://doi.org/10.3758/MC.36.8.1403

Rubin, D. C., Rahhal, T. A., & Poon, L. W. (1998). Things learned in early adulthood are remembered best. Memory & Cognition, 26(1), 3–19. https://doi.org/10.3758/BF03211366

Rubin, D. C., Wetzler, S. E., & Nebes, R. D. (1986). Autobiographical memory across the lifespan. In D. C. Rubin (Ed.), Autobiographical memory (pp. 202–221). Cambridge University Press.

Sakata, Y. (2024). Effects of interviewer age on the reminiscence bump in older adults’ autobiographical memories. Experimental Aging Research, 50(5), 727–741. https://doi.org/10.1080/0361073X.2023.2269802

Schrauf, R. W., & Rubin, D. C. (2001). Effects of voluntary immigration on the distribution of autobiographical memory over the lifespan. Applied Cognitive Psychology, 15(7), S75–S88. https://doi.org/10.1002/acp.835

Legal Authorities

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

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

State v. Chapple, 135 Ariz. 281, 660 P.2d 1208 (1983).

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

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

State v. Nordstrom, 200 Ariz. 229, 25 P.3d 717 (2001).

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

Fed. R. Evid. 602.

Fed. R. Evid. 702.

Ariz. R. Evid. 602.

Ariz. R. Evid. 702.

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

Mil. R. Evid. 602.

Mil. R. Evid. 702.

Mil. R. Evid. 1102.

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