What best describes the core aspect of teacher identity?

Concept — Teacher identity (professional identity) is a teacher’s answer to the question "who am I as a teacher?" Teacher-education research treats it as the self-understanding a teacher builds around what she is committed to — her convictions about children, about what counts as worthwhile knowledge, and about the purpose of schooling. Korthagen’s "onion" model orders a teacher’s professional make-up from the outside inward as environment, behaviour, competencies, beliefs, identity and mission: identity and the sense of mission lie at the innermost levels, immediately within the layer of beliefs, while competencies, behaviour and environment are the outer levels through which they are expressed.

Application — The stem asks which aspect is the core, so the test is constitutive versus expressive: which layer, if it changed, would change the teacher rather than merely change what is on show. A teacher’s personal values and beliefs decide how she reads a child’s misbehaviour, what she treats as evidence of learning, which methods feel right to her, and whether she keeps working with a learner who is struggling. Alter those convictions and the whole of her practice shifts, which is exactly what makes them constitutive.

Cross-check — Compare the four candidate aspects by what each one actually is:

• Personal values and beliefs — convictions about children, knowledge and the purpose of education; they supply the meaning a teacher gives to every teaching decision, so they constitute the identity itself.

• Subject expertise — a knowledge base and a competency. It is acquired and updated through study, and two teachers with identical mastery of the same syllabus can hold opposite educational commitments, so it expresses identity rather than constituting it.

• Professional attire — an outward code of dress, set largely by school or institutional norms; it can change with a change of workplace while the teacher stays the same person.

• Physical appearance — a set of bodily attributes that carry no educational commitment and lie outside professional formation altogether.

Result — The core aspect of teacher identity is the teacher’s personal values and beliefs; attire, appearance and even subject expertise are layers built around that core rather than the core itself.