Camilo A. Ordóñez Pinilla – /

William A. Jiménez-Leal -

Importance of the research

Dishonesty is a pervasive problem in human institutions, including political, academic, and private institutions, and also threatens informal institutions based on human interaction, as marriage or friendship.

Classic models understand honesty and dishonesty in a pure normative framework, giving a special explanatory role to legal, moral and social norms. For example, some accounts claim that honesty and dishonesty can be encouraged through legal enforcements, others claim that dishonesty is anchored on a lack of moral values and principles, and others claim that social co-regulation can be the central element to promoting honesty.

Since there are both conceptual and empirical problems in normative-based approaches to honesty and dishonesty (see our paper about these problems at, we are proposing a new cognitive approach to understand the key factors associated to honest and dishonest behaviors. In our approach, beliefs about the justice of the world and experiences of being treated justly or unjustly are crucial factors in order to understand the motivations behind honesty and dishonesty.

Our research can have an important impact in the promotion of honesty in social institutions: establishing the role of the belief in justice and the role of experiencing justice/injustice in the motivation of honest and dishonest behaviors, and providing psychometrical tools to measure what kind of belief in justice (justice as necessity, justice as equity, justice as deservingness) can affect honest and dishonest behaviors.

Research methodology

First, we developed psychometrical scales for measuring the degree in which people believe that the world is just according to three different conceptions of justice: justice as need, justice as equity, justice as necessity. The scale for the concept of justice as necessity is a validation in our sample and our country of the scale by Dalbert (1993). The scales for the concept of justice as necessity and as equity has been developed by us and require a full psychometrical validation.

Second, we developed experiments to manipulate experiences of justice and injustice and to check how such experiences affect the performance of participants in an honesty task: a task where only the participants know the result of a random trial and report the result -having the chance to give an honest or dishonest report- to reclaim a monetary reward, given that higher the reported result is, higher the monetary reward is.

Sample size

For the experiment, we conducted a power analysis using G-Power, using as parameters an alpha of 0.05, our number of conditions as predictors, and a small effect size (by convention 0.02). According to this analysis, the minimum sample size we need is n=1050. We use a small effect size as parameter because previous research about honesty in lab conditions has shown that dishonesty is presented in these conditions but in small effect sizes.

In addition, the validation of the 2 scales (having 35 items each one) requires a total of 700 participants, 350 for each one. This calculation uses a rule of thumb from Nunally (1978) of using a proportion #participants/#items of 10:1.

So, the study requires a total of 1350 participants.

Study’s cost

The platform where the experiment is programed (Qualtrics) estimates the time needed for each participant in 17 minutes average. Test conducted by us confirmed that estimation.

Hence, we calculate a payment of £ 2.00 for each participant. This payment is fixed for participation. So, we need £ 2.00 x 1350 = £ 2700.

Since our design includes giving a monetary reward according to the performance in the honesty task (ranging from £ 2.00 to £ 3.00), and our ethics board recommends that at the end of the study every participant receives the maximum reward, we need extra-founds of bonus: £ 3.00 x 1350 = £4050.

Hence, for the experimental work we need £6750. Adding the Prolific fee of 33%, we need a total of £6750 + £2228= £8978

For the validation of the scales, the estimated time is 9 minutes average. Test conducted by us confirmed that estimation.

Hence, we calculate a payment of £ 1.00 for each participant. This part of the study does not require bonus. So, we need £ 350, and adding the Prolific fee, a total of £ 466.

The total cost of the complete study is £ 9444.


The study is pre-registered at

Open Access

All materials, raw data and R scripts used for statistical analysis will be available through, giving the financial credits to Prolific.