Who am I ? Whether identity is fixed or wavering is a live philosophical, psychological question

 Does one's personal identity waver or is it fixed?

Short answer: it depends on what you mean by “personal identity.” Some senses of identity are relatively stable; others are fluid. Whether identity is fixed or wavering is a live philosophical, psychological and empirical question — and different frameworks give different answers.
Key distinctions

• Numerical (strict) identity: the metaphysical claim that you are the very same entity across time. Philosophers debate criteria (body, brain, soul, or psychological continuity).

• Qualitative identity/self-concept: the set of traits, memories, values, roles and stories you take to be “who I am.” This is clearly changeable to varying degrees.

• Numerical (strict) identity: the metaphysical claim that you are the very same entity across time. Philosophers debate criteria (body, brain, soul, or psychological continuity).

• Qualitative identity/self-concept: the set of traits, memories, values, roles and stories you take to be “who I am.” This is clearly changeable to varying degrees.

Philosophical perspectives

• Locke: personal identity = continuity of memory/psychological continuity. If you remember past experiences, you’re the same person in the relevant sense.

• Animalism: you are the same biological organism through time (the living human animal).

• Reductionism (Derek Parfit): there’s no simple “deep” self; what matters are psychological connectedness and continuity, not an indivisible soul. Identity can be a matter of degree.

• Bundle theory (Hume): the self is just a bundle of perceptions—no underlying fixed substance.

• Narrative identity: identity is the life-story you construct; it can be revised as you reinterpret events.

• Eastern (Buddhist) view: anatta (no-self) — the idea of a permanent, unchanging self is an illusion.

Psychology and neuroscience

• Personality traits show substantial stability, especially after early adulthood, but change gradually across the lifespan and can change more abruptly after major life events.

• Memory and brain changes (development, injury, dementia) can substantially alter who a person seems to be.

• Brain evidence suggests continuity depends on ongoing physical and functional continuity of the brain, but the brain is plastic, so psychological identity is malleable.

When identity seems to “waver”

• Adolescence and early adulthood (identity formation).

• Major life transitions (migration, career change, trauma, illness).

• Mental illness, addiction, or neurodegenerative disease.

• Moral or spiritual conversion: people can adopt radically different values and life narratives.

Practical takeaway

• Some core continuity usually exists (biological and psychological), but personal identity is partly constructed and revisable. Think of identity as having both stable and fluid elements: enough continuity to hold a life together, and enough plasticity to allow growth or change.

• If stability is desired, practices that support continuity (narrative reflection, stable relationships, consistent values) help. If change is desired, therapy, new experiences, and deliberate reframing can facilitate it.

Needles-in-a-haystack examples and thought experiments

• Ship of Theseus and Parfit’s fission cases probe strict identity.

• Real-world: severe amnesia can make someone seem like a different person; gradual personality shifts (e.g., after a stroke) illustrate partial change.

If you want to go deeper

• Read Derek Parfit’s Reasons and Persons (reductionism), John Locke (memory theory), David Hume (bundle theory), Daniel Dennett and Thomas Metzinger (philosophy of mind), Erik Erikson (identity development), Dan P. McAdams (narrative identity), and accessible discussions of Buddhist no-self.

Conclusion
There’s no single, universally accepted answer. If you treat identity as an unchanging metaphysical core, many traditions deny such a thing. If you treat identity as the pattern of psychology, relationships, and narrative that makes you recognizable over time, it’s mostly continuous but also changeable.