Public Release: 

Policemen, thieves and ordinary people apply different logic when making decisions

University of Granada

This release is available in Spanish.

A study conducted by the University of Granada, in collaboration with the University of Cambridge, revealed that policemen and ordinary people reason differently than criminals when making decisions. That is, they reason in different ways. This conclusion might have significant implications on criminal jurisdiction.

This research was conducted by Rocío García-Retamero from the Department of Experimental Psychology and Behavioural Physiology of the University of Granada, and Mandeep K. Dhabi from the Institute of Criminology (University of Cambridge, United Kingdom).

For the purpose of this study, García Retamero and Dhami took a sample of 120 people that participated voluntarily. The sample consisted of 40 expert criminals, 40 expert policemen and 40 students unrelated to criminal activities. The policemen had been working for the security forces for an average of 19.4 years and their work had been mainly centred on investigating robberies.

The criminals claimed to have committed an average of 57.2 robberies. They were convicted criminals that had been imprisoned for burglary just once. The students specified the number of times that they had been victims of a theft (only an average of 0.6 times).


The participants -policemen, expert criminals and students unrelated to any criminal activity- were asked to estimate the importance of certain factors when predicting the chances of a home being broken into. Some of the factors were: full/empty mail box, lights on/off, the fact of the home being a flat or a house, or the presence of neglected plants. They were asked to classify them on the basis of the extent in which their presence could help to predict a successful housebreaking. For example: for the factor "home security systems" they were posed with the following situation: "Imagine two houses: one with a burglar alarm and other without it. In what degree is it more likely that the house without alarm is broken into?. To answer this question, the participants had to draw a circle around a value ranging from 0 to 100 on a ten-point interval scale. Then, participants were classified on the basis of their strategy.

Significant differences

The results revealed that the two groups of experts (burglars and policemen) had different perceptions of the importance and classification of each factor. The perception of the policemen was more similar to that of ordinary people than to that of burglars. Thus, policemen and ordinary people agreed that the method employed to break into the house was the most relevant factor, when it comes to foreseeing a successful housebreaking. Conversely, the burglars considered that the most relevant factor was the presence of a burglar alarm.

Although the answers of both groups of experts differed, they were more consistent than those of ordinary people. That is, the experts employed more consistent criteria when it came to use different ways to express them, and they agreed with experts of their own group in a higher degree.

The conclusions drawn from this research -according to the researchers: "make a new contribution to study the differences between experts and inexperienced people. It also might have important implications regarding criminal jurisdiction and decision-making patterns".



García-Retamero, R., & Dhami, M. K. (2009). Diferencias entre expertos y noveles en las estimaciones sobre el poder predictivo de las claves en el ámbito de la delincuencia. Psicothema, 21, 376-381.

Garcia-Retamero, R., & Dhami, M. K. (2009). Policías, ladrones y gente corriente: Diferencias entre expertos y noveles en el uso de estrategias para la toma de decisiones. Ciencia Cognitiva, 3:2, 42-45.

García-Retamero, R., & Dhami, M. K. (2009). Take-the-best in expert-novice decision strategies for residential burglary. Psychonomic Bulletin and Review, 16,163-169.

García-Retamero, R., Hoffrage, U., & Dieckmann, A. (2007). One cue is not enough: Combining fast and frugal heuristics with compound cue processing. Quarterly Journal of Experimental Psychology, 60, 1197-1215.


Rocío García-Retamero. Department of Experimental Psychology and Behavioural Physiology of the University of Granada. Phone number: +34 958 246 240. E-mail:

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