Snap Shot
- The question: Does picturing an event that never occurred raise a person’s belief that it occurred, and can repeated imagining lead to a false memory?
- What the research shows: In laboratory studies, imagining a childhood event raised confidence that it had occurred for a minority of events, and repeatedly imagining simple actions led people to remember performing actions they had only imagined. Effects grow with repetition and sensory detail, and imagination combined with other suggestion raises false memory rates in implantation studies.
- What it does not show: One session of imagining a childhood event usually produces a small change in belief; across studies, imagined events typically remained judged unlikely. The research does not show that any particular memory, accusation, or confession arose from imagination, and imagining a context that was actually experienced, as in the cognitive interview, is a different procedure.
- The law: Expert testimony on imagination inflation is governed by Rule 702 (as amended in 2023) and, in courts-martial, Houser; it is general and may not declare a memory or confession false (Brooks; Lindsey). A defendant may present the circumstances in which a confession was obtained (Crane), and Arizona admits general memory testimony in the court’s discretion (Chapple; Nordstrom).
- Issues for each side: Prosecutors can point to the modest size of single-session effects and the protective value of recorded, non-suggestive interviews, without treating confidence that grew over time as corroboration; defense counsel can show how repeated, detailed imagining raises belief and false recollection, tied to evidence that such techniques were used.
Imagination inflation is the finding that imagining an event can increase a person’s confidence that the event actually happened. The term was coined to describe a laboratory result: people who imagined certain childhood events became, on average, somewhat more confident that those events had happened to them than they were about comparable events they had not imagined (Garry et al., 1996). Related research shows that repeatedly imagining simple actions can lead people to remember performing actions they only imagined, and that imagination is one of the ingredients that raise false memory rates when researchers suggest entire childhood events.
The finding reaches court because some practices in therapy, investigative interviewing, and interrogation ask a person to picture, visualize, or describe the way something could have unfolded. Whether the person is a complainant in therapy, a witness who is uncertain about a detail, or a suspect asked to imagine how a crime would have been committed, the research bears on whether the account that follows reflects memory, inference, or imagination. The same research is sometimes overstated. Its central measures are confidence and belief ratings, and most studies found modest effects.
This paper describes the original demonstrations, imagined actions, imagination in false memory studies, the debate about effect size, the mechanisms, the settings in which imagination is used, the limits of the evidence, and the governing law.
The Original Demonstrations
In the study that named the effect, college students rated the likelihood that various childhood experiences, among them putting a hand through a window, had happened to them. Two weeks on, they were guided to imagine some of the events they had rated as unlikely, and then rated the whole list again. Confidence rose for more of the imagined events than of the events not imagined; in a tabulation of the results, 34% of imagined events and 25% of events not imagined received higher ratings (Garry et al., 1996, as tabulated in Brewin & Andrews, 2017; the original report was not reviewed for this paper). The study measured confidence that an event occurred. It did not ask participants to describe memories, and it did not show that participants came to remember the imagined events as experienced.
Later studies identified other routes to the same result. Asking participants to construct an explanation for a childhood event, rather than to picture it, also raised confidence that it had occurred (Sharman et al., 2005), and one study found that repeated exposure to an event’s description, by paraphrasing it, raised confidence about as much as imagining it (Sharman et al., 2004). These findings suggest that the effect is not unique to imagery; processing an event in ways that make it come to mind more readily can strengthen the sense that it happened.
Imagined Actions and Repetition
A second line of research tested memory for recent, simple actions rather than childhood events. Participants heard action statements such as “break the toothpick” and either performed the action, imagined performing it, or only heard it. In a later session they imagined various actions once, three times, or five times. On a final test, the more often an action had been imagined in the second session, the more likely participants were to remember having performed it in the first session, including actions they had only heard and actions that had not been presented in the first session at all (Goff & Roediger, 1998). The same pattern held for bizarre actions, such as sitting on dice, as well as familiar ones (Thomas & Loftus, 2002). False memories were greatest when participants were required to include sensory detail in their imaginings, and in those conditions false memories were more often accompanied by a sense of recollection rather than mere familiarity (Thomas et al., 2003). In a study conducted during a walk around a college campus, imagining familiar or bizarre actions just once led to some false recollections of having performed them two weeks later (Seamon et al., 2006).
A 2023 experiment added an asymmetry relevant to statements by accused persons. After performing some actions and imagining others, participants were instructed to repeatedly deny an action they had performed and to repeatedly claim an action they had only imagined. Afterward, 16 of 30 participants (54%) wrongly indicated that they had performed the imagined action they had falsely claimed, but none indicated that they had only imagined an action they had performed and falsely denied (Bücken et al., 2023). This was one small study (N = 30), not yet replicated so far as identified here, and the actions were trivial, but the result suggests that performed actions resist being erased more than imagined actions resist being added.
From Belief to Memory: Imagination in Implantation Studies
Imagination also appears as an ingredient in studies that try to create memories of whole events. In one study, participants who imagined a medical procedure that, the researchers established, does not occur came to report more beliefs and more memories about having experienced it than before (Mazzoni & Memon, 2003). In an implantation study in which participants were told that they had spilled a punch bowl at a wedding as children, those asked to imagine the event across interviews were more likely to report clear false memories than those asked only to think about it, about 25% compared with 9% (Hyman & Pentland, 1996, as tabulated in Brewin & Andrews, 2017; the original report was not reviewed for this paper).
Across eight implantation studies coded under one system (423 participants), 30.4% of participants were classified as having formed a false memory overall, and the rate was highest (46.1%) in the condition in which the suggestion included self-relevant information and an imagination procedure without a photograph; most participants in the pooled data did not form a false memory (Scoboria et al., 2017). A study of a fabricated adolescent crime, which used repeated visualization across suggestive interviews, reported a 70% false memory rate in that single study (Shaw & Porter, 2015); a reanalysis with stricter criteria found a substantially smaller share (Wade et al., 2018), and the original author disputed that reanalysis (Shaw, 2018). Because imagination in these studies was combined with a credible source asserting the event, repetition, and other suggestion, the results cannot be attributed to imagination alone. The implantation research and its debate are covered in the paper on false memory.
How Large Is the Effect?
The size of the effect has been debated since the first studies. Pezdek and Eddy (2001) contended that the original results reflected regression toward the mean: when they repeated the procedure, ratings for events initially rated unlikely rose while ratings for events initially rated likely fell, whether or not the events were imagined. Garry et al. (2001) replied that the effect remained after regression was taken into account. The issue matters because studies typically choose events that participants initially rate as unlikely, and such ratings tend to rise somewhat on retesting regardless of what happens in between.
A systematic review addressed magnitude directly. It identified 19 datasets in 16 articles testing imagination inflation for childhood events. Of the 17 datasets that reported a valid test, 11 found a statistically significant effect and 6 did not. In 13 of 14 datasets reporting the relevant means, the increase attributable to imagination was one point or less on a scale of about eight points, and average ratings remained in the lower half of the scale; the authors concluded that imagination inflation increases belief by a small amount, so that imagined events are still thought unlikely to have happened (Brewin & Andrews, 2017). Commentators disputed the review’s broader conclusion that susceptibility to false childhood memories is limited, arguing that even a small percentage of false memories matters and that rates rise across interviews (Nash et al., 2017), and that false belief and imagery are important outcomes short of vivid recollection (Scoboria & Mazzoni, 2017).
Research on who is susceptible has found little that predicts the effect in an individual. Inflation effects in two different imagination tasks were unrelated within the same participants (Calvillo et al., 2019). A 2025 preregistered study of 279 participants found that a general tendency to distrust one’s memory was unrelated to imagination inflation, and that inducing memory distrust did not increase the effect (Dudek & Polczyk, 2025). These findings argue against testimony that a particular person is the type to form beliefs from imagination, and equally against a claim that a particular person is immune.
Why It Happens
Two explanations, which are not mutually exclusive, have support. One rests on fluency: once an event has been imagined, it comes to mind more readily, and that readiness can be read as a sign of having lived it. The other rests on source monitoring: imagining generates details, such as images, sounds, and feelings, that resemble the details of perceived events, so that later the person may remember the content but misjudge its source (Garry & Polaschek, 2000). The finding that more sensory detail produces more false recollection supports the second explanation (Thomas et al., 2003). Both fit the source-monitoring framework, under which people infer from a memory’s qualities whether it reflects a real event (Johnson et al., 1993).
In a 2025 brain-imaging study, judgments that a faint visual stimulus was real tracked the combined strength of activity in a visual region, whether from perception or imagery, and fluctuations in that activity predicted confusions between imagining and seeing (Dijkstra et al., 2025). The study concerned immediate perception of simple patterns, not memory for past events, and cannot be used to evaluate a particular person’s memory.
Imagination in Therapy, Interviews, and Interrogation
Concern about imagination in therapy arose in the 1990s. In a survey of U.S. and British practitioners, 71% reported using at least one technique, such as hypnosis or dream interpretation, to help clients recover suspected memories of childhood sexual abuse (Poole et al., 1995), and a review of the period argued that guided imagery combined with repetition, authority, and expectation could lead some clients to develop false memories (Lindsay & Read, 1994). Brewin and Andrews (2017) noted that some therapeutic practices might resemble the conditions of these studies while emphasizing that the studies produced modest changes in belief. The surveys are decades old; later research continues to link reports of recovered memories to particular therapeutic practices (Patihis & Pendergrast, 2019), and the recovered-memory debate has its own paper.
In investigative interviewing, it is important to distinguish imagining what might have happened from mentally reinstating what did. The cognitive interview asks witnesses to mentally reinstate the context of the event they experienced, and a meta-analysis found that it reliably increased correct information, with a smaller increase in incorrect details (Memon et al., 2010). The imagination inflation research does not show that context reinstatement creates false memories. Its concern is with questions that ask a witness to picture, guess, or elaborate on details the witness does not remember, particularly when repeated.
In interrogation, Henkel and Coffman (2004) offered a theoretical analysis, not an experiment, of how coercive tactics could, within the source-monitoring framework, contribute in some cases to a belief in guilt and to false memories supporting it. A 2025 scientific review recommended recording interrogations in their entirety, limiting false-evidence and minimization tactics, and adopting science-based interviewing (Kassin et al., 2025); a complete recording also shows whether an admission followed imaginative or hypothetical questioning or preceded it. Interrogation is addressed further in the False Confessions resources.
Limits of the Evidence
Most imagination inflation studies use college students, childhood events chosen because participants initially rate them unlikely, or simple laboratory actions, and they measure confidence or belief on rating scales. Those outcomes differ from the vivid, detailed memories that are at issue in court, and the extent to which a small shift in a rating translates into a sincere report of a remembered event is not settled. Regression toward the mean complicates the interpretation of single-group designs. Studies that produce full false memories combine imagination with other suggestion, so imagination’s separate contribution in those settings is uncertain. Real-world conditions may be more powerful, through repetition over months, authority, and personal stakes, or less powerful, because real events are often rich, distinctive, and continuously remembered. Finally, all of this is group research: it describes how imagination can shift belief and memory on average, and it cannot establish that a particular person’s memory or admission resulted from imagining.
Questions to Ask About This Research
When Garry et al. (1996) is cited, counsel should ask what was measured: higher confidence ratings for a minority of childhood events, not the creation of memories. When the effect is described as large, counsel should ask how much it changed ratings on the scale used, given Brewin and Andrews’s (2017) finding of increases of one point or less in most studies and Pezdek and Eddy’s (2001) regression argument. When implantation rates such as 46.1% (Scoboria et al., 2017) or 70% (Shaw & Porter, 2015) are cited, counsel should ask whether imagination was the only manipulation and how a false memory was coded, given the reanalysis by Wade et al. (2018).
Counsel should also ask whether the research applies to this person: whether the person was in fact invited to picture the event or to guess at it; how often and in how much detail; whether the questioning is recorded; and whether the account in question was given before or after that questioning. When the effect is dismissed because questioning was brief, counsel should ask whether it was repeated or asked for sensory detail, because Goff and Roediger (1998) and Thomas et al. (2003) found larger effects under those conditions. These questions are explained in “Reading Research Claims: A Guide for Attorneys” on this site.
Imagination Inflation and the Law
Federal and Military Standards
Expert testimony on imagination inflation is governed by Federal Rule of Evidence 702, which as amended December 1, 2023, requires the proponent to show that it is more likely than not that the testimony rests on sufficient facts or data, is the product of reliable principles and methods, and reflects a reliable application of those methods to the case. Daubert v. Merrell Dow Pharmaceuticals, Inc. (1993) assigned trial judges a gatekeeping role, and Kumho Tire Co. v. Carmichael (1999) extended that obligation to all expert testimony, including non-scientific technical or specialized knowledge. Because the research consists largely of modest changes in belief ratings, the “reliable application” requirement asks whether the expert can explain how those findings fit the facts of the case. In courts-martial, Military Rule of Evidence 702 tracks the federal rule, and under Military Rule of Evidence 1102 the 2023 federal amendment became part of the military rule in 2025 (Joint Service Committee on Military Justice, 2025); practitioners should confirm current text. Admissibility is assessed under the six factors of United States v. Houser (1993), and an expert may not vouch for or against a witness’s credibility (United States v. Brooks, 2007). When a confession is admitted, the defendant has a constitutional right to present evidence about the circumstances in which it was obtained, because they bear on its credibility (Crane v. Kentucky, 1986).
Arizona
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), Arizona’s leading case on memory expert testimony, held that excluding such testimony was an abuse of discretion on its facts, and State v. Nordstrom (2001) confirmed that admission otherwise rests in the trial court’s discretion and may be limited to general factors. Experts may not opine on whether a particular witness is truthful or accurate (State v. Lindsey, 1986, 149 Ariz. at 475), so testimony on imagination inflation is confined to the research and the conditions it describes.
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. A single act of imagining a childhood event typically produces a small change in belief, and in most studies imagined events were still judged unlikely. Full false memories in the research have generally required imagination combined with a credible source asserting the event, repetition, and other suggestion. Mentally reinstating the context of an experienced event, as in the cognitive interview, is supported by research and is distinct from imagining unremembered events. Prosecutors are well positioned to protect the evidentiary value of statements by ensuring that interviews and interrogations are recorded in their entirety and that questioning asks for what the person remembers rather than what he or she can picture or suppose.
The research also counsels caution. Repeated and detailed imagining can lead people to remember performing actions they only imagined, and those false memories can be accompanied by a sense of recollection. Where an account, or an admission, first appeared or expanded after a person was asked to visualize, speculate, or construct an explanation of the events, the factfinder is entitled to consider that sequence. Testimony or argument that treats confidence that grew over successive sessions as corroboration goes beyond the research.
Special Issues for Defense
The research supports several propositions defense counsel can legitimately present. Imagining an event can increase confidence that it occurred, repeated imagining of actions can produce memories of having performed them, and sensory detail and repetition strengthen the effect. Imagination is among the conditions that raised false memory rates in implantation studies. Expert testimony explaining these principles, together with evidence that a complainant, witness, or accused was asked to imagine or visualize events, is a legitimate way to help the factfinder evaluate how an account developed.
The research also counsels caution about the limits that apply to the defense. Most effects are modest, measured as belief ratings rather than memories, and the original findings were debated on statistical grounds. The research cannot show that a particular memory, accusation, or confession resulted from imagination, and an expert may not say so; the expert analyzes the process (questions, repetition, exposure), not the truth of the account. Context reinstatement in a properly conducted interview is not the same as imagination inflation, and the argument is strongest when tied to a record of repeated, detailed imaginative questioning before the account was given. The same principles apply to every person whose account is at issue, including the accused.
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
Brewin, C. R., & Andrews, B. (2017). Creating memories for false autobiographical events in childhood: A systematic review. Applied Cognitive Psychology, 31(1), 2–23. https://doi.org/10.1002/acp.3220
Bücken, C. A., Otgaar, H., Mangiulli, I., Ramakers, N., & Merckelbach, H. (2023). Can false denials turn fact into fiction? The effect of false denials on memory for self-performed actions. Psychological Research, 87(3), 816–825. https://doi.org/10.1007/s00426-022-01695-7
Calvillo, D. P., Vasquez, A. N., & Pesavento, A. (2019). Imagination inflation effects are unrelated across two imagination inflation tasks. Psychology of Consciousness: Theory, Research, and Practice, 6(1), 90–98. https://doi.org/10.1037/cns0000178
Dijkstra, N., von Rein, T., Kok, P., & Fleming, S. M. (2025). A neural basis for distinguishing imagination from reality. Neuron, 113(15), 2536–2542.e4. https://doi.org/10.1016/j.neuron.2025.05.015
Dudek, I., & Polczyk, R. (2025). Memory distrust and imagination inflation: A registered report. PLOS ONE, 20(8), Article e0327638. https://doi.org/10.1371/journal.pone.0327638
Garry, M., Manning, C. G., Loftus, E. F., & Sherman, S. J. (1996). Imagination inflation: Imagining a childhood event inflates confidence that it occurred. Psychonomic Bulletin & Review, 3(2), 208–214. https://doi.org/10.3758/BF03212420
Garry, M., & Polaschek, D. L. L. (2000). Imagination and memory. Current Directions in Psychological Science, 9(1), 6–10. https://doi.org/10.1111/1467-8721.00048
Garry, M., Sharman, S. J., Wade, K. A., Hunt, M. J., & Smith, P. J. (2001). Imagination inflation is a fact, not an artifact: A reply to Pezdek and Eddy. Memory & Cognition, 29(5), 719–729. https://doi.org/10.3758/BF03200474
Goff, L. M., & Roediger, H. L., III. (1998). Imagination inflation for action events: Repeated imaginings lead to illusory recollections. Memory & Cognition, 26(1), 20–33. https://doi.org/10.3758/BF03211367
Henkel, L. A., & Coffman, K. J. (2004). Memory distortions in coerced false confessions: A source monitoring framework analysis. Applied Cognitive Psychology, 18(5), 567–588. https://doi.org/10.1002/acp.1026
Hyman, I. E., Jr., & Pentland, J. (1996). The role of mental imagery in the creation of false childhood memories. Journal of Memory and Language, 35(2), 101–117. https://doi.org/10.1006/jmla.1996.0006
Johnson, M. K., Hashtroudi, S., & Lindsay, D. S. (1993). Source monitoring. Psychological Bulletin, 114(1), 3–28. https://doi.org/10.1037/0033-2909.114.1.3
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
Kassin, S. M., Cleary, H. M. D., Gudjonsson, G. H., Leo, R. A., Meissner, C. A., Redlich, A. D., & Scherr, K. C. (2025). Police-induced confessions, 2.0: Risk factors and recommendations. Law and Human Behavior, 49(1), 7–53. https://doi.org/10.1037/lhb0000593
Lindsay, D. S., & Read, J. D. (1994). Psychotherapy and memories of childhood sexual abuse: A cognitive perspective. Applied Cognitive Psychology, 8(4), 281–338. https://doi.org/10.1002/acp.2350080403
Mazzoni, G., & Memon, A. (2003). Imagination can create false autobiographical memories. Psychological Science, 14(2), 186–188.
Memon, A., Meissner, C. A., & Fraser, J. (2010). The cognitive interview: A meta-analytic review and study space analysis of the past 25 years. Psychology, Public Policy, and Law, 16(4), 340–372. https://doi.org/10.1037/a0020518
Nash, R. A., Wade, K. A., Garry, M., Loftus, E. F., & Ost, J. (2017). Misrepresentations and flawed logic about the prevalence of false memories. Applied Cognitive Psychology, 31(1), 31–33. https://doi.org/10.1002/acp.3265
Patihis, L., & Pendergrast, M. H. (2019). Reports of recovered memories of abuse in therapy in a large age-representative U.S. national sample: Therapy type and decade comparisons. Clinical Psychological Science, 7(1), 3–21. https://doi.org/10.1177/2167702618773315
Pezdek, K., & Eddy, R. M. (2001). Imagination inflation: A statistical artifact of regression toward the mean. Memory & Cognition, 29(5), 707–718. https://doi.org/10.3758/BF03200473
Poole, D. A., Lindsay, D. S., Memon, A., & Bull, R. (1995). Psychotherapy and the recovery of memories of childhood sexual abuse: U.S. and British practitioners’ opinions, practices, and experiences. Journal of Consulting and Clinical Psychology, 63(3), 426–437. https://doi.org/10.1037/0022-006X.63.3.426
Scoboria, A., & Mazzoni, G. (2017). Invited commentary on Brewin and Andrews (2016). Applied Cognitive Psychology, 31(1), 28–30. https://doi.org/10.1002/acp.3264
Scoboria, A., Wade, K. A., Lindsay, D. S., Azad, T., Strange, D., Ost, J., & Hyman, I. E. (2017). A mega-analysis of memory reports from eight peer-reviewed false memory implantation studies. Memory, 25(2), 146–163. https://doi.org/10.1080/09658211.2016.1260747
Seamon, J. G., Philbin, M. M., & Harrison, L. G. (2006). Do you remember proposing marriage to the Pepsi machine? False recollections from a campus walk. Psychonomic Bulletin & Review, 13(5), 752–756. https://doi.org/10.3758/BF03193992
Sharman, S. J., Garry, M., & Beuke, C. J. (2004). Imagination or exposure causes imagination inflation. American Journal of Psychology, 117(2), 157–168. https://doi.org/10.2307/4149020
Sharman, S. J., Manning, C. G., & Garry, M. (2005). Explain this: Explaining childhood events inflates confidence for those events. Applied Cognitive Psychology, 19(1), 67–74. https://doi.org/10.1002/acp.1041
Shaw, J. (2018). How can researchers tell whether someone has a false memory? Coding strategies in autobiographical false-memory research: A reply to Wade, Garry, and Pezdek (2018). Psychological Science, 29(3), 477–480. https://doi.org/10.1177/0956797618759552
Shaw, J., & Porter, S. (2015). Constructing rich false memories of committing crime. Psychological Science, 26(3), 291–301. https://doi.org/10.1177/0956797614562862
Thomas, A. K., Bulevich, J. B., & Loftus, E. F. (2003). Exploring the role of repetition and sensory elaboration in the imagination inflation effect. Memory & Cognition, 31(4), 630–640. https://doi.org/10.3758/BF03196103
Thomas, A. K., & Loftus, E. F. (2002). Creating bizarre false memories through imagination. Memory & Cognition, 30(3), 423–431. https://doi.org/10.3758/BF03194942
Wade, K. A., Garry, M., & Pezdek, K. (2018). Deconstructing rich false memories of committing crime: Commentary on Shaw and Porter (2015). Psychological Science, 29(3), 471–476. https://doi.org/10.1177/0956797617703667
Legal Authorities
Crane v. Kentucky, 476 U.S. 683 (1986).
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. Nordstrom, 200 Ariz. 229, 25 P.3d 717 (2001).
United States v. Brooks, 64 M.J. 325 (C.A.A.F. 2007).
United States v. Houser, 36 M.J. 392 (C.M.A. 1993).
Ariz. Sup. Ct. Order R-23-0004 (2023) (amending Ariz. R. Evid. 702, effective Jan. 1, 2024).
Fed. R. Evid. 702.
Ariz. R. Evid. 702.
Mil. R. Evid. 702.
Mil. R. Evid. 1102.
Related topic papers: False Memory · Misattribution of Memory · Source Monitoring · Recovered and Repressed Memory · Suggestibility of Children’s Memory · Hypnosis and Memory
Related topics from Arizona Forensic Services: False Confessions · False Confessions: Suggestibility