Terms beginning with P
Which psychology terms begin with P?
8 entries beginning with P: P-Value, Piaget's Theory of Cognitive Development, Placebo Effect, Post-Traumatic Stress Disorder, Preregistration, Psychodynamic Therapy, Psychological Safety, Publication Bias.
From the PsychologyOrbit knowledge base on 2 November 2026.
P
P-Value
The probability of obtaining data at least as extreme as those observed, if the null hypothesis and every other assumption of the statistical model were true. It is not the probability that the hypothesis is false.
Piaget's Theory of Cognitive Development
Jean Piaget's account of children as active builders of knowledge who pass through four stages of thinking. The stages have not survived intact, but the idea that children reason differently rather than simply knowing less still shapes education.
Placebo Effect
A genuine change in a person's condition produced by the psychosocial context of a treatment — expectation, conditioning, ritual and the clinical relationship — rather than by any specific active ingredient.
Post-Traumatic Stress Disorder
A condition that can follow exposure to actual or threatened death, serious injury or sexual violence, characterised by intrusive re-experiencing, avoidance, negative changes in mood and thinking, and heightened arousal.
Preregistration
Specifying a study's hypotheses, design and analysis plan in a time-stamped, read-only record before the data are collected or examined, so that confirmatory claims can be distinguished from exploratory ones.
Psychodynamic Therapy
A family of therapies working with unconscious process, early relationship patterns, defence, and what happens between client and therapist, typically less structured and longer than behavioural treatments.
Psychological Safety
A shared belief within a team that it is safe to take interpersonal risks — to ask a question, admit a mistake, disagree or raise a concern — without being humiliated or penalised for it.
Publication Bias
The tendency for studies with significant or striking results to be published, and for null results to remain unpublished, which distorts the literature and inflates every estimate built from it.
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