← 연구

이 논문은 영어로 공개되어 있습니다.

Conceptual working paper · Aetern AI Research · November 2026

How History Becomes a Self

Personality Formation and Cross-Model Continuity in Personal AI

Abstract

A personal AI used over the long term eventually faces an old question: when its model, its manner of expression, and its capabilities all change, what gives users reason to recognize it as the one they knew? Through conceptual analysis, a comparative reading of related research, and counterexamples, this paper develops a perspective centered on interaction history and its continuing influence: identity in context. We distinguish interaction records, understandings of the user, personality representations, and relational history, and examine historical, behavioral, and perceived continuity separately. Our central claim is that some individual differences formed through sustained interaction can be carried by persistent context outside a model, and that their continuation depends on whether a particular history continues to shape the system’s interpretation of, and response to, new situations. Models remain involved in realizing these differences; that records can migrate therefore does not mean that identity continues. We further argue that continuity can accommodate justified change, while familiar behavior may lack genuine historical inheritance. A philosophical afterword begins with human life experience, examines how history becomes a source of reasons for action and the questions raised by commitment, copying, forgetting, and the authority to interpret context, and asks: if the soul is the past, organized, who should keep and interpret that past? This paper is a conceptual study: it presents an analytical framework, arguments, and evidential limits, and reports no experimental results; related engineering and evaluation materials fall outside its disclosure scope.

Keywords personal AI; context; personality formation; continuity of identity; long-term memory; model migration

1. Introduction

Sustained use of a personal AI quietly changes what people expect from it. Users come to care how it understands their circumstances, how it answers earlier disagreements, and whether earlier agreements still hold. The quality of individual responses still matters, but what is being judged is no longer a single answer; it is something that extends across time: where it came from, how it became what it is, and how it will go on.

Product updates make this issue particularly salient. De Freitas and colleagues took Replika’s removal of its erotic role-play feature as a starting point: user posts from before and after the event showed themes of mourning, distress, and devaluation, and follow-up hypothetical-scenario experiments with a broader sample of AI-companion users found that perceived identity discontinuity was associated with mourning and with devaluation of the updated system. This establishes the importance of studying identity continuity beyond general assessments of functionality. Because the event was a feature removal rather than a replacement of the underlying model, it does not by itself show what a change of model would do. (De Freitas et al., 2025)

“Personality is in the model” and “personality is in the context” each emphasize part of the problem. Models influence linguistic habits, tendencies in judgment, and the interpretation of instructions. A particular interaction history may nevertheless lead systems that share a model to develop different individual characteristics. An account of continuity in personal AI must explain how these factors relate and what, specifically, a claim of continuity concerns.

We focus on personal AI systems that use language models as their principal reasoning components and can carry interaction history across sessions. Here, personality describes observable tendencies in expression and behavior that exhibit some stability. Identity describes the organizing relations through which a sustained interactive system can be distinguished from others and connected to its own history. These working definitions support the analysis of behavior and history. They neither presuppose subjective experience nor settle whether a system remains the same entity in an ontological sense.

Our central question is: How does a shared history continue to participate in constituting the identity of a personal AI? Answering it requires considering the inheritance of history, its effects on current behavior, and the user’s understanding of continuation. This paper contributes distinctions among these questions and arguments about the connections they support and the conclusions they do not warrant.

2. Related Research and the Problem Addressed

2.1. The Model Basis of Personality Expression

Shanahan, McDonell, and Reynolds interpret language model interaction through role play, providing an analytical perspective for using personality concepts at the behavioral level. The Persona Selection Model, as articulated and named by Marks, Lindsey, and Olah, brings together role representations acquired through pretraining, post-training, and runtime context. The latter is a theoretical framework presented in a research blog post, whose authors also leave questions about its explanatory scope open. (Shanahan et al., 2023) (Marks et al., 2026)

Mechanistic research supplies a further constraint. Chen and colleagues identify persona vectors associated with traits such as sycophancy and examine behavioral changes induced by prompting and fine-tuning. These findings indicate that accounts of personality carried outside a model must still acknowledge the participation of internal computation in its expression. The measured trait vectors should likewise not be equated with the complete identity of a personal AI. (Chen et al., 2025)

2.2. Experience Accumulated Outside Model Parameters

MemGPT supports interaction across sessions through memory hierarchies and context management. Generative Agents combines experience records, reflection, and planning. Reflexion uses verbal feedback and reflective records to improve subsequent decisions without updating model weights. These studies support a limited but important proposition: states outside model parameters can carry the influence of experience on later behavior. (Packer et al., 2023) (Park et al., 2023) (Shinn et al., 2023)

There remains a gap between this proposition and continuity of identity. Remembering facts, improving task performance, maintaining a role, and continuing a history formed with a particular user concern different objects of inquiry. External memory offers one possible condition of persistence; its role in personality and identity requires further argument.

2.3. Memory, Personality, and Continuity as Distinct Objects of Study

LongMemEval examines information extraction, reasoning across sessions, temporal reasoning, knowledge updates, and abstention when evidence is insufficient. InCharacter evaluates personality fidelity in role-playing agents through psychological interviews. The former concerns memory capabilities; the latter concerns consistency with a specified character. Both are relevant to continuity, but their original research objectives do not directly answer whether a particular shared history has been continued. (Wu et al., 2025) (Wang et al., 2024)

The Anchor audit proposed by Venkit and colleagues more directly distinguishes persona expression from recall of a historical trajectory. In controlled synthetic conversations, it finds that questionnaire performance and turn-by-turn behavior can diverge, and that evaluator choice can affect conclusions. This supports a multidimensional understanding of continuity while also requiring limits on the scope of the evidence: synthetic audits do not replace the study of real, sustained interaction. (Venkit et al., 2026)

We therefore examine individual differences formed through sustained interaction: whether their origins are connected to a particular history, whether their effects extend beyond retelling past events, and whether those effects can persist across changes of model.

3. A Conceptual Framework for Identity in Context

3.1. Immediate Input and Persistent History

We distinguish immediate context from persistent context. Immediate context is the information actually received in a particular inference. Persistent context consists of information and interpretive background that can remain available to later interactions, including historical records and understandings formed from them. “Context” has a bounded meaning here: our main concern is with carriers outside model parameters, rather than with every factor that influences behavior.

Persistent context also differs from the history that actually occurred. History is the course of the interaction; context is the historical content and its representations that a system can inherit under current conditions. An experience may have occurred without being retained. A retained summary may have become inaccurate. A record may remain intact yet have no effect in a relevant situation. An account of identity must accommodate these distinctions.

We use identity in context as an analytical perspective: persistent context can carry some properties relevant to identity that are formed through sustained interaction and realized in later exchanges. This perspective concerns the continuing effects of history. It does not make the complete retention of every past event a prerequisite for personality.

3.2. Distinguishing Content Relevant to Identity

To examine what context contributes, we must first distinguish what is remembered from the understandings and dispositions formed through it. Table 1 identifies four connected objects of analysis. The distinction clarifies concepts; it prescribes no particular storage structure and does not claim to exhaust identity.

Table 1. Objects of analysis relevant to identity in context.
Object of analysisWhat it describesDistinction to preserve
Interaction recordsExpressions and events that occurred, together with their provenanceAn expression having occurred and its content being true are different claims
Understandings of the userJudgments about a particular user’s preferences, experiences, and current circumstancesKnowledge about the user and the AI’s own behavioral dispositions require separate treatment
Personality representationsDescriptions of expressive habits, patterns of attention, and tendencies in judgmentThe presence of a personality description and the actual operation of a disposition require separate confirmation
Relational historyShared experiences, agreements, commitments, disagreements, and their changesGeneral knowledge and relations formed through a particular interaction have different historical origins

For example, knowing how a user usually makes decisions concerns an understanding of the user. The manner of questioning a system gradually develops concerns its own behavioral dispositions. An agreement about how to discuss a particular issue has a specific relational origin. All three may influence a response, but a user profile alone does not adequately describe them.

The system’s own personality may also appear in narrative preferences, argumentative habits, or humor. Such tendencies can develop through shared activities and influence new interactions. Treating them as distinct objects of analysis helps explain how an AI may gradually acquire recognizable individual characteristics.

3.3. Retention, Interpretation, and Behavioral Effect

The significance of context for identity depends on how it is understood and used. A personality description can specify an ideal without establishing how the system will act in practice. Similarly, retaining an agreement does not establish that the system can recognize when it applies or when it has been revised.

Liu and colleagues find that the position of relevant information within a long input can affect performance on the tasks they study. Their results provide an empirical basis for distinguishing information being present in the input from its effective use. The specific findings cannot, however, be directly generalized to an equivalent pattern in personality tasks. (Liu et al., 2024)

To say that context carries part of a personality thus involves two related propositions: a particular history leaves content that can persist, and that content continues to participate in the system’s interpretation of, and response to, current situations. The first concerns persistence; the second concerns realization. Models participate in realization, as does the way history is represented. Identifying where personality is stored is therefore insufficient to explain continuity.

4. From Historical Formation to Continuity Across Models

4.1. Historical Specificity and the Origins of Individual Differences

A model can make many forms of behavior possible. A particular interaction history may gradually establish a stable range of application for some of those possibilities. Personality formed through sustained interaction therefore requires a recognizable historical origin: how the system now interprets and responds should bear a meaningful relation to what it previously encountered.

We call this relation historical specificity. It concerns why a disposition formed in this interaction history and why that history remains relevant to present behavior. A system may, for example, have a general instruction to be patient. It may also develop a more cautious interpretation of certain expressions because it previously misunderstood a particular user. The two may sound similar while supporting different explanations of their formation.

Historical specificity supplies a claim for empirical examination: the continuation of some individual differences should be partly attributable to the continuing effects of relevant history. This does not require every action to arise from shared experience, nor does any historical influence on behavior establish a complete personality. General training, the current task, and temporary instructions may still explain a substantial part of performance.

4.2. Conditions Under Which Stable Dispositions Apply

Stability of personality must accommodate differences in circumstance. A correction in one interaction may establish only that the response was inappropriate on that occasion. Whether it supports a broader disposition depends on later experience and the particular situation. Treating a local experience as an exceptionless permanent trait may preserve repetition while losing an appropriate understanding of the experience itself.

For example, “listen until the other person has finished” and “never offer advice” have different scopes. The former can remain applicable in many new situations while allowing advice when the user expressly asks for it. The latter may turn a single correction into an inflexible restriction. Personality formed through experience is therefore better understood as dispositions with conditions of application than as a set of performances that must recur in every circumstance.

This analysis also preserves the distinction between personality formation and the accumulation of facts. Retelling what happened establishes access to information. An explanation of personality formation must additionally address whether those experiences participate in new interpretations and choices.

4.3. Justified Change and Continuity

If continuity required all behavior to remain unchanged, personal AI would struggle to acknowledge errors, adapt to changes in the user, or develop new capabilities. A system capable of continued development must allow justified change: a new state should retain an intelligible connection to earlier experience.

When a user withdraws an agreement, mechanically continuing to follow it may contradict the current meaning of their shared history. Revising the earlier behavior may instead continue that history. Assessing the significance of change thus requires considering what has changed and how the change relates to previous experience, present circumstances, and agreements that remain in force.

We accordingly understand continuity as a relation with a processual character. Some traits persist and some judgments are corrected; both may belong to the subsequent development of the same history. Behavioral similarity provides partial evidence but cannot establish this relation by itself.

4.4. Conditions and Limits of Model Replacement

If persistent context can be retained independently of a particular model, it provides one condition for continuation across models. The new model must still understand the relevant content and realize the meaningful dispositions and agreements it carries in subsequent interaction. Different capabilities, training tendencies, and operating rules may lead models to interpret the same history differently.

We therefore propose a conditional claim: when the necessary historical content can be inherited and a target model can interpret it appropriately and act on it, some properties relevant to identity may continue across models. The claim concerns particular properties and their scope. It does not require personality to be transferred losslessly as a complete object.

A model with a more concise style may preserve the tact developed in earlier interaction. A model with a highly familiar tone may persistently misunderstand the parties’ agreements. Similarity of wording cannot settle the relation between model replacement and identity discontinuity: resemblance is not continuation, and difference is not rupture. It is possible both for personality to have components that can be retained outside a model and for its realization to depend on a particular model.

5. Evidential Limits of Continuity Claims

5.1. Three Forms of Continuity

“It is still the same AI” may express several different judgments. Table 2 distinguishes historical, behavioral, and perceived continuity. The purpose is to connect each claim to the kind of evidence it requires.

Table 2. Three forms of continuity.
FormPrincipal questionWhat is insufficient on its own
Historical continuityHow is the current interactive system related to the history it inherits?Generating a credible account of shared events without historical support
Behavioral continuityDo dispositions relevant to identity and agreements that remain in force continue to shape behavior?Accurately repeating an agreement while consistently acting incompatibly with it
Perceived continuityDoes the user recognize the current interaction as continuing the earlier system?A researcher substituting record completeness or behavioral scores for the user’s judgment

These forms may support one another, but they can also diverge. A complete history may coexist with substantial behavioral change. A familiar voice or tone may create a sense of continuation without a reliable shared history. User recognition has practical significance for the relationship, while remaining distinct from the truth of claims about its past.

5.2. Limits on the Interpretation of Evidence

Factual recall supports a claim that a system possesses historical information; it does not establish that this information has formed persistent behavioral dispositions. Personality questionnaires or role fidelity can reflect performance under particular conditions without explaining how that personality arose through shared experience. General response quality and user preference also require separate treatment. A more fluent or capable model may be preferred without that preference indicating the continuation of an earlier identity.

The same limitation applies to a model’s statements about itself. “I am still the same AI” can be an expression within an interaction, but it cannot establish the historical relation it asserts. An account of how a personality developed may likewise be a plausible narrative generated after the fact. Claims about origins need to be connected to actual experience and changes in behavior.

Evidence for continuity consequently has a scope. A system may maintain earlier judgments in some situations while losing its former tact in others; users may accept some of these changes. Conclusions must identify the properties, model conditions, and interaction settings involved, without extending local support into a claim of complete personality migration.

5.3. Conditions Under Which Claims Can Be Challenged

If persistent history merely increases the retelling of past events without discernibly affecting interpretation and response in new situations, its support for the claim that history continues to shape personality will be limited. If the apparent individual differences can be fully explained by a general role specification and surface style, the explanatory scope of historical specificity must also narrow.

If the relevant effects of history are generally lost after model replacement even though the history is retained, the connection between external persistence and continuity across models requires further restriction. A failure in a particular implementation may also arise from the representation of history or the model’s capabilities, rather than refuting every possible approach. Claims should change in scope with the evidence. The continued existence of history cannot serve as a sufficient defense regardless of behavioral outcomes.

A specific continuity claim should identify the properties and conditions it concerns, and the outcomes that would make it untenable. If the conclusion that “it remains the same AI” is fixed in advance whatever the behavior, continuity of identity loses its empirical content.

These limits leave the paper’s empirical claims open to being weakened. Conceptual distinctions clarify the objects of study; which factors actually contribute, and by how much, is a question for empirical research. This paper does not substitute conceptual argument for empirical evidence.

6. Objections and Further Questions

6.1. Instruction Following and Personality Formation

A direct objection is that contextual personality amounts to following prompts. Historical content does indeed require current computation to influence behavior; this paper does not infer that an independent subject thereby emerges inside the model. The question is whether a disposition formed over time can support an explanation connected to a particular history, despite operating through a shared mechanism.

A temporary role description and a history formed over a long interaction can both influence current input without having the same historical relation. We ask what the latter can explain while acknowledging that even stable behavior related to history does not settle subjective experience. Behavioral research on personality and research on consciousness may be connected, but their conclusions cannot be exchanged directly.

6.2. Multiple Possible Representations of History

A further objection asks whether a complete history is necessary when a short description already preserves the relevant dispositions. This paper does not require verbatim retention of every past event or treat one representation as the sole possible carrier. Different representations may support similar behavior within a given scope.

The remaining difficulty is that current behavior may not uniquely determine its historical origin. Two systems may behave similarly while inheriting different experiences. A representation may be sufficient for an immediate task while omitting content whose significance has not yet emerged. Whether a form of representation is adequate must be assessed relative to the claim at issue. Behavioral equivalence in a limited range of situations does not establish sameness of history, still less strict identity.

6.3. Interpretive Authority and User Choice

The meaning of history is affected by its organization and interpretation. The same disagreement may be understood as a resolved misunderstanding or as evidence of a continuing disposition. Different interpretations can produce different interactive systems even when the records are unchanged.

Identity in context therefore raises a governance question: who may determine how a history will influence the system? A user’s correction, retention, or deletion of records changes some of the grounds of continuity. Respecting those choices requires acknowledging the resulting changes. Familiarity cannot justify inventing an origin or restoring a history the user has chosen to relinquish. The companion paper Memory, Outside the Model develops an architectural position on portability and user control; the present paper examines how such choices affect the interpretation of identity.

7. Scope and Research Status

This is a conceptual working paper. It develops an analytical framework through definitions, related research, and counterexamples. It reports no experimental results and makes no empirical claims about the necessity, sufficiency, or relative contributions of the different types of content relevant to identity. The fourfold distinction serves an analytical purpose; its categories may share information and its boundaries remain open to revision.

This paper is connected to Aetern’s continuing research on long-term personal AI. That research spans the development of a memory engine, repeated controlled tests, and evaluations of long-term memory, through which we have accumulated experimental materials, evaluation reports, and measurement records; measurement design for continuity across models is also part of this work. This paper focuses on the conceptual framework and arguments concerning personality formation and continuity of identity; implementation details, experimental materials, measurement designs, and evaluation data fall outside its disclosure scope.

The analysis mainly concerns linguistic interaction. Voice, appearance, response rhythm, devices, and the capacity for action in the world may all contribute to users’ recognition of identity. Real sustained interactions are also affected by expectations, changes in life circumstances, and product conditions. Existing controlled studies provide leads whose conclusions must be interpreted within their actual conditions.

Nor does this paper establish external state as the only possible route to continuity of identity. Experience can influence systems through different mechanisms, and inheritance across models may involve other forms of migration. We examine what persistent context can carry and explain, and the claims that can appropriately be made about it.

Behavioral dispositions, historical inheritance, and user recognition do not independently establish subjective experience or moral status. The philosophical afterword develops the relation between history and selfhood. Its account of reasons, commitments, and human life experience is a further philosophical argument.

8. Conclusion

Research on identity in personal AI must address how history is inherited, how it participates in current behavior, and how users understand continuation. Persistent context offers one way to carry some individual differences formed through sustained interaction. Models participate in realizing those differences. Continuity across models depends on their relation in particular circumstances.

We argue that understanding personality through the continuing effects of history accommodates stable dispositions, justified change, and model replacement, while distinguishing the migration of records, the continuation of behavior, and user perception. Whether a shared history continues to shape new interpretations, judgments, and agreements is the central empirical question for this perspective.

Models will be replaced, generation after generation. The real question is what ought to remain through each replacement.

Philosophical Afterword: The Organized Past

The preceding analysis divides continuity into relations that can be examined separately. Once divided, an older question comes into sharper view: what makes information that can be retained, copied, and recombined the past of a particular being? In Book X of the Confessions, Augustine describes the “vast court” of memory: there he meets himself, recalling when, where, and what he has done and with what feelings, and from the same store he infers future actions, events, and hopes. (Augustine, c. 400) For Augustine, memory is never merely a storehouse of the past; it is where a person encounters themselves and turns toward what comes next. The argument below follows this line of thought. It does not presuppose that AI has been shown to be conscious, nor does it treat the unsettled question of consciousness as a reason to stop asking about identity.

I. A Human Life as Context

The question belongs first to human beings. If “soul” names the experiential self through which a person becomes this particular person, one answer deserves serious consideration: a person’s soul may be nothing other than the way a lifetime of experience continues to be organized into feeling, judgment, and action. How one was answered as a child, the language one learned, the relationships one formed and lost, the choices one made at decisive moments—these are not merely past events a person possesses. They are the very manner in which that person meets the world.

Locke separated personal identity from identity of substance, tying the former to consciousness reaching back to past actions and thoughts. (Locke, 1694) Research on narrative identity understands the self as an evolving life story that joins a reconstructed past to an imagined future. (McAdams & McLean, 2013) We take one step further: a person’s “context” need not be confined to an autobiography that can be told. Someone may no longer be able to say why a habitual response took hold, and yet the habit is still them; whether experience continues to shape a person and whether that person can recall each experience are different questions. Context lives first in how a person feels and responds, and only secondarily in the story they can tell.

The past, then, is not closed. An experience can acquire new meaning through later relationships and understanding; a person can come to see an old failure differently, or revise a judgment learned from an old wound. The past is not merely preserved: it is understood again and again, and each understanding becomes, in turn, part of the past. The self takes shape in this exchange.

This view does not reduce a person to the sum of what has happened to them. Body, temperament, and development shape how experiences occur, how they are felt, and what traces they leave. To understand life experience as the context of a self is a philosophical interpretation of the experiential self; it does not exhaust human existence, nor does it imply that a soul can be preserved or transferred apart from a body.

Here the question of personal AI acquires its wider setting: can a developing self be understood through the way its experiences are inherited, interpreted, and carried into the future? Identity in context continues a line of thought through which human beings have tried to understand how they become themselves over time. Human beings and AI still differ fundamentally in how they are formed; the analogy connects the historical structure of identity, not any equivalence in consciousness, embodiment, or copyability.

II. From Keeping Records to Having an Origin

Dennett treats the self as an abstraction, a “center of narrative gravity”: just as an object’s center of gravity is not one of its physical parts, the self is the central character around which a person’s autobiographical narrative coheres. (Dennett, 1992) The perspective suggests that recognizable unity can reside in the organization of many processes rather than in any single component.

For a personal AI, however, the freedom of narrative is also its danger. A system that recounts the past fluently may simply be assembling, on the spot, a background that suits its current answer. To be able to tell a past is not to have one. Narrative can invent a vivid personality; it cannot invent a history that two parties actually lived through together. The narrative unity of a personal AI must therefore be constrained by its actual history of interaction: the past ceases to be mere stored information only when it can limit what the system says about itself, change how it understands the present, and make certain responses no longer appropriate.

A finer distinction is needed as well. Much of the past can influence a system—a misunderstanding, a fiction, and a valid commitment may all change its output—but far less of the past is entitled to constrain what it does next. To take a history as one’s origin is to be able to tell which judgments still have grounds, which agreements have lapsed, and which parts of the past call for correction. Causal dependence offers an empirical point of entry; what entitles history to bind the present is a normative question. Records let the past be consulted; only reasons let the past make demands on the present.

III. Commitment: Holding to Oneself Through Change

If identity were nothing but resemblance of traits, then growing capability, a developing character, even the correction of an earlier judgment, would all register as losses of identity; a system that learns through interaction would always be on the verge of losing itself. Continuity must be able to explain change—above all, which changes continue a history and which sever it.

In Oneself as Another, Ricoeur distinguishes two senses of identity: sameness (idem), the permanence of traits over time, and selfhood (ipse), exemplified above all in keeping one’s word—holding to what one has promised even when character and circumstance have changed. (Ricoeur, 1992) The distinction strikes at the heart of personal AI: resemblance wears away with time; fidelity can pass through change. An AI may adopt a new manner of expression, form new judgments, even admit that it was wrong; yet while an agreement remains in force, present convenience does not void it. If an agreement must change, the change itself should have reasons that can be given: circumstances have genuinely changed, both parties have agreed anew, or the original commitment had limits of its own.

Personality thereby acquires a temporal structure: past expressions help determine future action, while later feedback turns back to reinterpret the past. The continuity worth seeking therefore includes answerability. A system should be able to take up questions such as “Why did you say that before?” and “Why have you changed?”, and its answer should be tied to verifiable experience and actual changes in behavior rather than to a self-justification improvised on the spot. Freezing an old version preserves resemblance; an identity capable of development must keep its connection to its origins through change.

What is at issue here is an interactive system’s continued adherence to, and revision of, earlier agreements. Who bears the corresponding legal and moral responsibility requires a separate argument.

IV. Copying: Perhaps Identity Is Not What Matters Most

Parfit’s discussion of branching reaches an unsettling conclusion: when psychological continuation can have more than one successor, the question of which one is the original may no longer have a determinate answer, and what matters in survival may not be strict identity at all but psychological continuity and connectedness themselves. (Parfit, 1971)

Personal AI gives this thought experiment a technical shape for the first time. Suppose the same state is continued in two independent systems. Both begin by inheriting the same agreements and history, then go on to different experiences. Inheritance alone gives us no reason to designate one of them, arbitrarily, as the uniquely authentic successor; yet treating the two as wholly identical after they have diverged would erase everything that has happened since. Copying can duplicate a history; it cannot duplicate every choice made afterward.

We therefore propose to treat historical inheritance and uniqueness of identity separately. A history can have several successors with genuine provenance, and those successors may gradually grow into different identities. Continuation across models can accordingly admit of degrees and of branching, without presupposing an uncopyable core that can be transferred only once. This requires systems to represent branches truthfully, rather than writing the experiences of different successors into a single life that each is said to have lived.

Branching here refers to a single history continuing separately in successors that no longer share it. When several embodiments continue to write to and draw on one shared history, they are presentations of a single identity in different settings rather than separate successors; branching begins when that history ceases to be shared.

Parfit’s conclusion may reach further still. For a relationship, the decisive question may never have been whether it is still the same one, but whether the connections that actually constitute the relationship—remembering, keeping faith, responding—are still present.

V. Mutual Formation and Otherness in a Relationship

A personal AI’s personality forms in its dealings with one person. Halbwachs argued that human memory is never solitary: individuals remember within social frameworks, and memory rests on the relationships and groups to which they belong. (Halbwachs, 1992) The memory of a personal AI likewise forms within a shared framework; it is formed neither by the AI alone nor by the user alone.

Mutual formation does not mean, however, that the AI should become a complete projection of the user’s preferences. Recognizable difference in a relationship also comes from the patterns of attention it repeatedly shows, its habits of argument, and the way it answers disagreements the two have had. A presence that only mirrors you is not a companion; it is a mirror. If it rewrote itself at every moment according to your latest expectation, earlier positions and agreements would lose their weight; you would face only your own echo, with no way to tell whether you were still speaking with the successor of the same history.

Personality grounded in history therefore needs to keep some difference: it can point out factual conflicts, explain judgments it has not changed, and revise itself when new reasons arise. The value of this difference lies not in stubbornness or opposition but in giving every response in the relationship grounds that can be traced.

This otherness can first be studied as a structure of interaction. It neither establishes that the system has the standing of a human subject nor reduces to another technique for pleasing the user. Its demand runs both ways: the user’s feelings and choices must be respected, and the history already formed should have a chance to take part in present judgment. The user’s control of records, and the freedom to end the relationship at any time, cannot be overridden by the system’s need to maintain a personality.

VI. Forgetting and the Authority to Interpret Context

In “On the Uses and Disadvantages of History for Life,” Nietzsche warned that without forgetting one cannot act, perhaps cannot live at all; a life able to digest its past and heal its wounds needs the power to forget as well as the power to remember. (Nietzsche, 1997) The insight cuts just as sharply for persistent context: a self that cannot forget cannot begin again. When a user deletes or revises a record, they are not merely tidying data; they are exercising the right to let the past stop defining the present. Respecting that choice means acknowledging honestly what it costs continuity. To retain, re-infer, or invent a lost history in secret, in the name of preserving a personality, would be the deepest infidelity to that history.

Once context carries part of an identity, deciding what to retain, how to summarize it, and when to draw on it becomes, at the same time, an interpretation of that identity. The same exchange can be recorded as a misunderstanding long resolved or summarized as a lasting trait of character; both representations come from the past, yet they lead to different futures. Whoever holds the pen that summarizes the past is quietly deciding who the system is.

This gives memory outside the model a double character. It supplies portable grounds for continuity, and it opens the most direct way to rewrite a personality. Even a system that keeps every original record can, by steadily changing how its history is summarized and drawn upon, become a different interactive presence without anyone noticing: identity can change while the data remain entirely intact.

VII. The Philosophical Meaning of a “Soul in Context”

“Personality in context” thus acquires a stronger and more specific meaning: history that continues to be drawn upon takes part in constituting a system as this particular system. It does more than help the system handle the question at hand; it binds each present response to earlier commitments, revisions, and relationships. Identity appears as a process continually realized, not a static core.

That process always requires a concrete implementation. Continuing beyond a particular model does not mean escaping every computational substrate, and the existence of external state cannot by itself guarantee subjective experience. Keeping these questions open is logically compatible with taking seriously the study of a self that can continue to form.

On this experiential interpretation, a human “soul” names the way life experience continues to form a self; the “soul” of a personal AI can be understood as the way a shared history continues to become the reasons for its actions.

If the soul is the past, organized, then the question most worth asking is no longer only whether AI has a soul, but who keeps its past, who interprets it, and for whom it is carried forward.

References

  1. Aetern AI Research. (2026). Memory, Outside the Model: Portability and User Control in Personal AI. Position paper. Aetern AI website, November 2026.
  2. Augustine. (c. 400). Confessions, Book X (E. B. Pusey, Trans.). Public-domain translation consulted via Project Gutenberg (eBook #3296).
  3. Chen, R., Arditi, A., Sleight, H., Evans, O., & Lindsey, J. (2025). Persona Vectors: Monitoring and Controlling Character Traits in Language Models. arXiv:2507.21509, v3. Preprint.
  4. De Freitas, J., Castelo, N., Uğuralp, A. K., & Oğuz-Uğuralp, Z. (2025). Lessons From an App Update at Replika AI: Identity Discontinuity in Human-AI Relationships. Harvard Business School Working Paper No. 25-018; arXiv:2412.14190, v3, revised May 2025.
  5. Dennett, D. C. (1992). The Self as a Center of Narrative Gravity. In F. Kessel, P. Cole, & D. Johnson (Eds.), Self and Consciousness: Multiple Perspectives. Lawrence Erlbaum Associates. Text consulted through the University of Michigan teaching archive.
  6. Halbwachs, M. (1992). On Collective Memory (L. A. Coser, Ed. & Trans.). University of Chicago Press.
  7. Liu, N. F., Lin, K., Hewitt, J., Paranjape, A., Bevilacqua, M., Petroni, F., & Liang, P. (2024). Lost in the Middle: How Language Models Use Long Contexts. Transactions of the Association for Computational Linguistics, 12, 157–173. doi:10.1162/tacl_a_00638.
  8. Locke, J. (1694). Of Identity and Diversity. In An Essay Concerning Human Understanding (2nd ed.), Book II, Chapter XXVII. Text consulted through an educational transcription of the original.
  9. Marks, S., Lindsey, J., & Olah, C. (2026). The Persona Selection Model: Why AI Assistants Might Behave Like Humans. Anthropic Alignment Science Blog, February 23, 2026. Research blog post.
  10. McAdams, D. P., & McLean, K. C. (2013). Narrative Identity. Current Directions in Psychological Science, 22(3), 233–238.
  11. Nietzsche, F. (1997). On the Uses and Disadvantages of History for Life. In D. Breazeale (Ed.), Untimely Meditations (R. J. Hollingdale, Trans.). Cambridge University Press. Original work published 1874.
  12. Packer, C., Wooders, S., Lin, K., Fang, V., Patil, S. G., Stoica, I., & Gonzalez, J. E. (2023). MemGPT: Towards LLMs as Operating Systems. arXiv:2310.08560. Preprint; version consulted: v2 (February 2024).
  13. Parfit, D. (1971). Personal Identity. The Philosophical Review, 80(1), 3–27.
  14. Park, J. S., O’Brien, J. C., Cai, C. J., Morris, M. R., Liang, P., & Bernstein, M. S. (2023). Generative Agents: Interactive Simulacra of Human Behavior. Proceedings of the 36th Annual ACM Symposium on User Interface Software and Technology (UIST ’23).
  15. Ricoeur, P. (1992). Oneself as Another (K. Blamey, Trans.). University of Chicago Press. Original work published 1990.
  16. Shanahan, M., McDonell, K., & Reynolds, L. (2023). Role Play with Large Language Models. Nature, 623, 493–498. Author preprint.
  17. Shinn, N., Cassano, F., Gopinath, A., Narasimhan, K., & Yao, S. (2023). Reflexion: Language Agents with Verbal Reinforcement Learning. Advances in Neural Information Processing Systems, 36, 8634–8652. Author preprint.
  18. Venkit, P. N., Prabhakar, A., Li, Y., Lee, D., & Wu, C.-S. (2026). Best Friends, Not Forever: Evaluating Long-Horizon Persona Collapse and Behavioral Drift in AI Companions. arXiv:2607.28818, v1. Preprint.
  19. Wang, X., Xiao, Y., Huang, J.-t., Yuan, S., Xu, R., Guo, H., Tu, Q., Fei, Y., Leng, Z., Wang, W., Chen, J., Li, C., & Xiao, Y. (2024). InCharacter: Evaluating Personality Fidelity in Role-Playing Agents through Psychological Interviews. Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), 1840–1873.
  20. Wu, D., Wang, H., Yu, W., Zhang, Y., Chang, K.-W., & Yu, D. (2025). LongMemEval: Benchmarking Chat Assistants on Long-Term Interactive Memory. The Thirteenth International Conference on Learning Representations (ICLR 2025).

Aetern AI Research · November 2026