The Psychology Index is an independent reference, written from scratch in plain English.
Independent reference
Psychology, explained plainly
Short, original explanations of the ideas psychologists use: what each one claims, what the evidence looks like, and where researchers still disagree.
Attitudes and behaviourCognitive dissonance
Leon Festinger's theory of how conflicting beliefs and actions create discomfort, and how people resolve it.
Relationships and developmentAttachment theory
How Bowlby and Ainsworth explained the bond between infants and caregivers, and how the idea was extended to adult relationships.
Self-regulationEgo depletion
The ego depletion theory held that self-control draws on a limited resource. Here is the claim and what large replications later found.
PersonalityFive factor model of personality
The Big Five traits explained: openness, conscientiousness, extraversion, agreeableness and neuroticism, and the model's limits.
MotivationSelf-determination theory
Deci and Ryan's account of motivation, built on the needs for autonomy, competence and relatedness.
Decision makingAnchoring and adjustment
Why an initial number pulls estimates toward it, how researchers explain anchoring, and where the effect is weaker.
How to use this index
Every entry covers one idea and is short enough to read in a couple of minutes. Each sets out the core claim, how researchers have studied it, and what remains uncertain. The further reading at the end points to primary papers and books, so you can check the source yourself.
Psychology changes as studies are repeated and methods improve. Some famous findings have held up well and others have not, and an entry should tell you which is which.
Where to start
The A to Z lists every entry. The overview pages on personality and close relationships are good starting points if you would rather begin with a whole field than a single concept.