Two research programmes shaped how psychology measures optimism, they started within a year of each other, and they measure different things. Almost every confusing claim about optimism scores comes from treating them as interchangeable.
Quick Answer: Scheier and Carver (1985) defined optimism as a generalised expectancy about the future, measured by asking what people expect. Peterson and Seligman (1984) approached it through explanatory style — the habitual way people explain why bad things happened. One looks forward, one looks back. They correlate modestly and are not interchangeable. This test uses the expectancy tradition.
1984: Explanations as a Risk Factor
Christopher Peterson and Martin Seligman arrived at optimism from the study of learned helplessness — work on why organisms stop trying after uncontrollable adversity.
Their 1984 paper reframed the question around explanation. When something goes wrong, people explain it to themselves, and the shape of that explanation varies systematically between people. A habitual pattern of permanent, sweeping and internal explanations for bad events, they argued, functions as a risk factor for depression.
Note what this measures: not what you expect next, but how you account for what already happened.
1985: Expectancy Inside Self-Regulation
Michael Scheier and Charles Carver came from a different direction — a model of how people regulate behaviour toward goals. In that model, expectancies decide whether effort continues or stops.
Their contribution was to argue that some people carry a generalised expectancy of good outcomes into situations where they have no specific information, and that this general leaning is measurable and stable. They built an instrument to measure it directly by asking about expectations.
One tradition asks what you expect. The other asks how you explain. Both got called optimism, and the confusion has never fully cleared.
Why the Two Are Not Interchangeable
- Different time direction. Expectancy is forward-looking; explanatory style is retrospective.
- Different measurement. One asks direct questions about expectations. The other codes how people explain events, originally from open-ended responses.
- Modest correlation. They share a name and a rough direction, and correlate about as much as you would predict from that — which is not enough to substitute one for the other.
- Different intervention implications. Explanatory style is a habit of description and responds to practice. Generalised expectancy is a disposition and moves slowly.
The Field's Own Caution
Optimism research arrived carrying an obvious risk: it sounded like self-help with citations, and the researchers knew it.
The response was conservatism about claims. The major reviews separate association from causation carefully, report modest effect sizes rather than dramatic ones, and are explicit that the behavioural pathway — engagement versus disengagement — carries more of the explanatory weight than the expectation itself. That restraint is why the construct survived the wider replication reckoning better than several of its neighbours.
Which One This Test Measures
The expectancy tradition. The ten items measure generalised outcome expectancy in the Scheier and Carver sense, with some overlap into baseline mood and self-regard, and they do not code explanatory style at all.
If your score sits lower than you expected, explanatory style is the more workable place to look, because a habit of description is more tractable than a disposition.
Read Your Own Position
The Optimism and Pessimism test places you on the expectancy dimension in about two minutes. The Locus of Control test is the closest measure to the explanatory tradition on the site, and the Grit test measures the persistence that both traditions treat as the outcome that matters.