Behaviour Change

PROPAGANDA FOR CHANGE is a project created by the students of Behaviour Change (ps359) and Professor Thomas Hills @thomhills at the Psychology Department of the University of Warwick. This work was supported by funding from Warwick's Institute for Advanced Teaching and Learning.

Monday, February 17, 2014

The Defence Attorney's Conundrum

The number of executions carried out in the US leads to some outrageous statistics when looking at interracial homicides; 264 black defendants have been executed for killing white victims compared to only 20 white defendants for killing black victims (Death Penalty Information Centre, 2014). One of the most important jobs for Defence Attorneys is selecting appropriate jurors; if they fail to do this, their entire case may be jeopardised. Unsurprisingly, Defence Attorneys will opt for choosing jurors who are most similar to their client as they are likely to give a more lenient sentence (the similarity-leniency hypothesis). But exactly how far does this similarity appeal extend? Kerr et al (1995) demonstrate that in certain situations similar jurors are likely to pass harsher judgements compared to dissimilar jurors (the black sheep hypothesis).

Two studies were conducted by Kerr et al (1995) in order to test the similarity-leniency hypothesis compared to the black-sheep hypothesis. They predicted that in cases where there is strong evidence against the defendant, jurors from a similar group (race, religion, etc) are likely to pass harsher judgements in a possible attempt to disassociate themselves from the defendant (i.e. the black sheep) and protect the group’s status. I will focus on Study 2 as it yielded much more interesting results whilst dealing with a prevalent issue within the courtroom; racial prejudice.

168 students were told that the experiment was looking at how jurors reached a verdict and that after an individual decision was made they would deliberate as part of a 12 person mock-jury. All white participants and roughly half of the black participants were told that they’d be a minority in the mock-jury (i.e. 2 white people with 10 black people and vice versa). Participants were asked to complete a booklet which simulated voir dire (the fancy term for seeing if jurors are prejudice) and then considered two of four cases involving child molestation; one with strong evidence against the defendant and the other weak evidence. Each case varied when it came to the race of the defendant and the race of the victim (this last one stayed the same in both cases that the participants considered). Participants were then asked to indicate whether they found the defendant guilty or not, how certain they were and what the sentencing should be.

By combining the verdict and confidence rating, the experimenters created an 18 point scale which they then formed into the table above (where +9 is absolute certainty of guilt and -9 is absolute certainty of innocence). Unsurprisingly, defendants were seen as more guilty the stronger the evidence against them was. The only exception to this was in the case of Black juror and defendant and white victim (-0.14). Although it is not clear why, Kerr et al stipulate that it could be because there was an increased sense of brotherhood from being an extreme minority (having 10 white jurors and a white victim could lead to the jurors feeling obliged to protect the defendant so as to eliminate racial bias).  

Comparing the rest of the results, as the below graph shows, when there was weak evidence against the defendant, the similarity-leniency hypothesis was upheld. Yet when the evidence was strong this effect was reversed and so the black-sheep hypothesis took place. There were no significant findings when it came to the actual sentencing procedure however.

So what does this mean for Defence Attorneys? In cases where they have little to go on (i.e. strong evidence against the defendant) they should take care and ensure that when trying to appeal to similarity, the particular race of the defendant is well represented within the jury to avoid the defendant being identified as the ‘black sheep’ of the group.

Death Penalty Information Centre (2014). National statistics on the death penalty and race. [ONLINE] Available at: [Last Accessed 17/02/2014].

Kerr, N., Hymes, A., Anderson, A., & Weathers, J. (1995). Defendant-juror similarity and mock juror judgements. Law and Human Behaviour, 19(6), 554-567.

Jamie Hart. 

1 comment:

  1. Well done, not an easy piece of research to describe, but you have managed it.


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