Cognitive effort is a behaviour that is widely assumed to co-determine individual achievement. Understanding the socioeconomic gradient in effort is crucial to evaluating the degree of social mobility and allows for the improvement of equality of opportunity. Thus, the aim of the EFFORT project is to answer three research questions.


Research questions:

Descriptive component.

  1. To what extent do children’s effort levels differ by parental socioeconomic background?

Analytical component.

  1. Can existing disparities in effort by social background be explained by (a) the intergenerational transmission of effort from parents to children, and (b) varying motivations and differential susceptibility to incentives?

Methodological component.

  1. What are the best techniques to measure cognitive effort and what are the strengths and weaknesses of measures routinely used in different scientific disciplines?


Theoretical approach:

As Figure 1 illustrates, social origin influences attainment through both ability and effort. The effect on effort is likely mediated by subjective effort dispositions, such as locus of control and time preferences. The type of motivation also plays a key role, namely, whether children make an effort as a result of an external reward or because they are committed to the task itself. All of these factors are taken into consideration in the research design of the EFFORT project.

Figure 1: Conceptual model of effort and social mobility.



The EFFORT project implemented a suite of experiments incorporating cutting methods from across the social and physiological sciences. The main component of the experiment featured almsot 1,400 children from across 36 schools in Madrid and Berlin. The children did three real effort tasks. Each task was a test of executive function, the mental faculty which neuroscientists identify with cognitive effort.

Each task pertained to a subdomain of cognitive effort. The Slider Task primarily covers the information processing and updating subdomain. In the slider task, the participants are presented with 48 horizontal lines. There is a dial on each line and the participant must adjust the dial so it is exactly at the midpoint. The Simon task tests the regulation and control subdomain. In the Simon task, participants had to tap a certain button on the keyboard when a left-pointing arrow appeared on screen and a different button when a right-pointing arrow appeared on screen. The arrows could appear left, centre or right. The third task was the “AX-Continuous Performance Task”, which tests cognitive flexibility. In this task, participants had to press a certain combination of buttons in response to a string of numbers. A visual overview of each task is given in Figure 2.

Figure 2: Overview of real effort tasks.

The students did the experiments under three incentive conditions: (i) an unincentivised condition; (ii) an incentivised condition, where they were rewarded with toys in proportion to their score; and (iii) a tournament condition, where they were rewarded with toys, and the top three highest-scoring were rewarded with a round of applause and a certificate.

Figure 3: Awarding of certificates in the Berlin lab-in-the-field.

The experiment was carried out between 2019 and 2022. In Madrid, the participants undertook the study in a laboratory environment on the campus of Universidad Carlos III. In Berlin, the experiments were implemented lab-in-the-field style, with researchers setting up the experiment in school classrooms.

Figure 4: The Madrid lab.

Besides the main experiment, the team also implemented several supplementary experiments, with assistance form researchers in cogntive and physiological sciences. These experiments included techniques like pupillometry and heart-rate monitoring. The team also implemented a study using a matched parent-child sample, in order to more directly investigate intergenerational transmission of effort dispositions.

The experimental data is complemented with survey data gleaned from the participating children, as well as parents and teachers.


Secondary data sources:

Although experiments provide the most adequate measures of effort, large-scale surveys are representative of the whole population, and thus allow for an in-depth analysis of between-group differences. The EFFORT team has complemented its analysis of the primary data with analyses of secondary datasets, including the Programme for International Student Assessment (PISA), the Longitudinal Surveys of Australian Youth (LSAY), and the German Socio-Economic Panel (SOEP).


Data availability

Data from the Madrid component of the project (n = 806) has been uploaded to the Universidad Carlos III de Madrid data repository. It is currrently under embargo and will become publicly available on 01/03/2027. Due to data protection provisions, data from the German component of the experiment cannot be made publicly available.

Link to dataset here.



UC3M Carlos III University of Madrid (UC3M) is a public university in Madrid, Spain. According to QS World University Rankings, it is ranked 12th in Europe and 34th globally, among universities established in the last 50 years. Many of its undergraduate and master’s programs are ranked as the best in Spain.
The WZB Berlin Social Science Center is an internationally renowned research institute in Berlin, Germany. It is the largest social science research center in Europe not affiliated with a university. Approximately 150 scientists from the fields of sociology, political science, economics, and law work at the WZB.
UNED The National University of Distance Education (UNED) is a distance learning and research university, with campuses all over Spain. It offers undergraduate and postgraduate degrees, as well as non-degree qualifications. With over 200,000 students, UNED is the largest university in Spain and the second largest in Europe.


This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. 758600 ).

Principal Investigator: Jonas Radl
Host Institution: Universidad Carlos III de Madrid
Execution period: March 1st, 2018 – February 29, 2024

Read more here: Community Research and Development Information Service website.