Developmental theories answer different questions. Attachment theory concerns relationships and responses to availability and distress; cognitive-developmental models concern how a child reasons; moral-developmental models concern the reasoning offered for a judgement. In an MRCPsych vignette, choose the model that addresses the evidence supplied rather than assigning a diagnosis from an age or a single observed behaviour.
This teaching guide was prepared in September 2026 using sources checked on 27 September: OpenStax's lifespan theories, its developmental overview and NICE's clarification of attachment terminology. All cases below are original educational examples.
Separate a developmental model from a diagnosis
A model organises observations and proposes relationships. Diagnostic criteria define a clinical category within a specified classification system. Neither function should be confused with a prediction of one child's future.
A child who is hesitant in an unfamiliar appointment has not thereby demonstrated an attachment disorder, cognitive delay or a particular moral stage. The context, relationship, language, experience and task demands matter. The examiner may provide a deliberately focused observation, but the answer should not exceed what it supports.
A useful first sentence in a written rationale is: "This question concerns the child's explanation of the problem, so a cognitive model is more relevant than an attachment label." That identifies the level of analysis before naming a theorist.
Understand attachment as a relationship-based framework
Bowlby's work emphasised attachment as a system related to proximity, security and the child's relationship with caregivers. Ainsworth's observational work distinguished patterns of behaviour in structured separation and reunion settings. Secure, insecure-avoidant and insecure-resistant patterns, with disorganised patterns described in later work, are not interchangeable with psychiatric diagnoses. The developmental overview provides the theoretical context.
For revision, ask what happens when the child is distressed, seeks support and responds to reunion. Do not reduce attachment to whether a child cries. Different behaviours can have different meanings depending on the relationship and situation.
NICE explicitly warns against using attachment disorder and insecure or disorganised attachment behaviour interchangeably. Its NG26 guidance concerns defined groups of children in, adopted from or at high risk of entering care, not an unrestricted diagnostic shortcut for every child. The terminology explanation and guideline scope establish those limits.
Apply cognitive-developmental reasoning without rigid age rules
Piaget's model describes changes in forms of reasoning, including the relationship between concrete tasks and more abstract operations. Concepts such as object permanence, conservation and perspective-taking address particular cognitive questions. They are not a single global score for maturity. OpenStax's account summarises the model and its limitations.
In a conservation task, the crucial observation is how the child reasons about an apparent transformation. If the child says that the quantity changes when the same material is placed in a taller container, identify the perceptual feature driving the answer. Do not conclude that an entire developmental profile has been established from that response.
Task wording, familiarity, language and support can affect performance. A rigid rule that every child of one age must succeed can turn a useful model into a misleading clinical judgement. State what the observation suggests and what further assessment would be needed.
Distinguish moral reasoning from moral behaviour
Kohlberg's model concerns the reason offered for a moral judgement. The same outward behaviour can be supported by different reasons, such as avoiding punishment, preserving social approval or appealing to a broader principle. A question that reports only what someone did may not establish the reasoning level. The lifespan-theories chapter explains this distinction and discusses limitations of the model.
For example, two fictional adolescents both return a lost item. One says they feared getting into trouble; the other explains a principle about how people should treat one another. The action is the same, but the stated justification is different. Do not award the supposedly higher stage because you approve of the action.
Cultural context and the assumptions built into a task also matter. A model developed through particular samples and forms of questioning should not be treated as a culture-free ranking of people's worth or character.
Compare models using one child vignette
A fictional child becomes upset when a caregiver leaves, struggles with an unfamiliar quantity task and says that rules matter because adults punish people who break them. These observations address different questions. The first concerns behaviour within a relationship and setting; the second concerns reasoning on a task; the third concerns the explanation given for following rules.
| Model or construct | Evidence it helps organise | What it cannot establish from this vignette |
|---|---|---|
| Attachment framework | Responses to distress, separation, support and reunion | A clinical attachment disorder from one appointment |
| Piagetian reasoning | The child's explanation of a concrete or abstract problem | Overall intelligence or a complete developmental assessment |
| Kohlbergian reasoning | The justification given for a moral judgement | Actual conduct in every situation or personal moral worth |
| Wider developmental formulation | Language, relationships, learning opportunities and functioning over time | A single cause for all observed difficulties |
The practical benefit of the table is to prevent one theory from swallowing the whole case. The model should illuminate a defined question rather than force unrelated observations into one label.
Four original developmental vignettes
Vignette one: reunion after an unfamiliar assessment. A young child is distressed when a caregiver leaves. On reunion, the child seeks contact and then resumes exploration. The question asks which attachment-related observations matter. The answer should focus on support-seeking and the use of the caregiver in regulating distress, while recognising that a brief fictional observation is not a formal classification procedure.
The tempting error is to classify solely from crying. Distress during separation is only one part of the sequence. Further information about context and repeated observations would be needed before drawing a clinical conclusion.
Vignette two: the transformed materials. A child says that a row of counters contains more counters after they are spread further apart, even though none were added. The question concerns the distinction between perceptual appearance and conservation of quantity. A cognitive-developmental explanation fits better than an attachment explanation because the target is reasoning about the transformation.
Now change the case: the child misunderstood the word "more" in an unfamiliar language. The apparent cognitive conclusion becomes less secure. Clarifying comprehension changes the interpretation before another theoretical label is added.
Vignette three: the same decision, different reasons. Two adolescents refuse to copy another student's work. One explains that they do not want punishment; the other describes obligations and fairness. The task is to compare the stated reasoning, not to decide which adolescent is a better person. Additional conduct outside the hypothetical situation is not supplied.
Vignette four: an overextended attachment label. A school report describes a child as having an attachment disorder because they are withdrawn in class. The appropriate response is to question the inference. Withdrawal has many possible explanations, and an attachment pattern or disorder cannot be established merely by attaching that term to an observed behaviour. NICE's terminology guidance is particularly relevant to this distinction.
Use a model-selection worksheet
For each question, write the observation, the construct being tested, the most relevant model and the limit of the conclusion. Add one piece of missing information that would change the interpretation. This makes revision more demanding than matching a theorist's name to a keyword.
An original example is: "The child judges quantity from container height; the construct is conservation; a Piagetian account is relevant; language comprehension and task familiarity remain uncertain." The final clause protects against treating a teaching vignette as a complete clinical assessment.
Use the Royal College's current syllabus information to check the intended examination scope. Per iatroX product information, September 2026, question-linked Socratic follow-ups can help test why an alternative model is less appropriate. The aim is not to make a model fit every child, but to explain what a particular model does and does not contribute.
Frequently asked questions
Is insecure attachment the same as an attachment disorder?
No. NICE explicitly distinguishes attachment patterns and difficulties from a recognised clinical attachment disorder.
Can age alone identify the correct developmental stage?
No. Consider the actual reasoning demonstrated, task demands, language and context rather than using age as a complete assessment.
Does Kohlberg's model classify whether someone is a good person?
No. It concerns the reasoning offered for moral judgements, not a ranking of personal worth or a guarantee of behaviour.