Expectancy-value theory
Motivation is the product of how likely you think success is and how much you value it.
What it means
Expectancy-value theory holds that motivation depends on two beliefs: how well you expect to do at a task (expectancy) and how much you value its outcome. The theory postulates a multiplicative interaction — expectancy times value — so that in principle motivation falls toward zero if either term is near zero; empirically, though, the two terms mostly add and the multiplicative effect, while real, is modest, so raising confidence still helps somewhat even when value is low. Developed by Atkinson and elaborated by Eccles and Wigfield, the framework distinguishes several kinds of value — interest, usefulness, importance, and the cost you subtract — and finds that value best predicts the choices people make while expectancy best predicts how well they perform. Its practical lever is that value, being partly learned, can be shifted without changing ability.
The disappearing multiplication sign
Atkinson's original formula, Ts = Motive x Probability x Incentive, made the interaction the whole point: change either factor and the product moves, and near-zero on one factor zeroes the result. Yet for more than two decades the multiplicative term all but vanished from published studies, because additive models (expectancy plus value) fit real data nearly as well, and interaction effects are hard to detect with ordinary regression on noisy self-reports. Nagengast and colleagues (2011) recovered it using latent-variable interaction models on roughly 399,000 fifteen-year-olds across 57 countries: the Expectancy x Value term was positive and significant, but small. So the clean 'collapses to zero' story is a theoretical idealization; in practice both terms mostly add, and their interaction is genuine yet modest.
Value drives choice, expectancy drives performance
The most durable finding from decades of Eccles-Wigfield studies is a division of labor between the two terms. Subjective task value, especially interest and perceived usefulness, is the better predictor of choice: which courses students take, which majors and careers they pursue, whether they persist. Expectancy, measured as ability self-concept, is the better predictor of actual performance, such as grades. This matters because the outcomes managers and educators care about often diverge: you can raise someone's confidence and lift their scores while doing nothing to make them choose the field again. Most of this evidence is correlational and self-reported, so the causal arrows are inferred rather than proven, but the choice-versus-performance split replicates across subjects, ages, and countries.
Cost, the forgotten component
For years 'value' was operationalized as intrinsic interest, attainment, and utility, while cost, the negatives you subtract, was named in theory but rarely measured. Flake and colleagues (2015) argued this was a serious omission and showed cost is distinct and multidimensional: effort demanded by the task itself, effort stolen from the rest of life, valued alternatives given up, and emotional strain such as anxiety. Crucially, cost is not merely low value; a course can be interesting and useful yet still feel too expensive to continue, and cost often predicts dropout and disengagement better than the positive value components do. Treating motivation as benefits minus costs, rather than benefits alone, explains many abandonments that high interest and confidence cannot.
Moving the levers, and what limits them
Because value is partly learned, it can be moved without touching ability. In a much-cited field experiment, Hulleman and Harackiewicz (2009) had ninth-graders periodically write about how course material connected to their own lives; interest and grades rose, with the largest gains for students who started with low success expectations. That is the theory's practical promise: a cheap utility-value nudge, not a pep talk about talent. The caveats are real. Effects are heterogeneous and concentrated among low-confidence students, some replications are weaker, and Eccles and Wigfield (2020) have since renamed the framework situated expectancy-value theory to stress that expectancies and values form in the moment, shaped by culture, identity, and context, not stable traits a single intervention permanently resets.
Examples
A student skips an elective not because she doubts she could pass, but because she sees no value in the subject — high expectancy, low value, so no motivation.
A colleague genuinely wants to get fit but is certain she will have quit by February, so she never joins the gym at all — the value is there, the expectancy is not.
An adult learner who loves the piano and plays well enough still stops lessons once practice starts eating every evening — not confidence or interest, but cost, tipping the sum.
A voter cares intensely about the outcome but is convinced her single ballot cannot swing a national election, so she stays home: high value, near-zero expectancy of impact.
A sales rep works the easy accounts and skips the biggest prospect: winnable, he thinks, but only after months of unpaid groundwork, so the cost term overwhelms the benefits.
First described in Atkinson (1957); elaborated by Eccles, Wigfield and colleagues (1983 onward).
Key references
- Eccles, J. S., & Wigfield, A. (2020). From expectancy-value theory to situated expectancy-value theory: A developmental, social cognitive, and sociocultural perspective on motivation. Contemporary Educational Psychology, 61, 101859. doi.org/10.1016/j.cedpsych.2020.101859
- Flake, J. K., Barron, K. E., Hulleman, C., McCoach, B. D., & Welsh, M. E. (2015). Measuring cost: The forgotten component of expectancy-value theory. Contemporary Educational Psychology, 41, 232-244. doi.org/10.1016/j.cedpsych.2015.03.002
- Nagengast, B., Marsh, H. W., Scalas, L. F., Xu, M. K., Hau, K.-T., & Trautwein, U. (2011). Who took the 'x' out of expectancy-value theory? A psychological mystery, a substantive-methodological synergy, and a cross-national generalization. Psychological Science, 22(8), 1058-1066. doi.org/10.1177/0956797611415540
- Hulleman, C. S., & Harackiewicz, J. M. (2009). Promoting interest and performance in high school science classes. Science, 326(5958), 1410-1412. doi.org/10.1126/science.1177067
- Atkinson, J. W. (1957). Motivational determinants of risk-taking behavior. Psychological Review, 64(6, Pt.1), 359-372. doi.org/10.1037/h0043445