Salacious alibi more credible if you lie about it at first

If you are suspected of a crime, you might be better off if you lie about an alibi in the first place and subsequently admit that you were in the company of an adulterous lover: it is even more credible than if you state this salacious alibi immediately. Legal psychologist Ricardo Nieuwkamp discovered this during his research on alibis. He carried out his project at Maastricht University with funding from the Open Competition of NWO.

An alibi is the claim of a suspect that he or she could not have committed the alleged crime because they were somewhere else at the time of the incident. In Nieuwkamp's study, the combination of a salacious alibi and changing alibi or sticking to the original one was investigated. Results from previous research had revealed that a salacious alibi is more credible and that as soon as the suspect changes an alibi, this is always associated with a decrease in credibility.

The current study revealed that a change in alibi can lead to more plausibility if there is an explanation for this. For example: the suspect lies about his original alibi because he is ashamed of staying with his lover, but comes clean later by admitting to the true circumstances.

Mistake or deliberate lie...

Nieuwkamp selected 150 participants (including 37 men) between the ages of 18 and 74 years, who were all given a fictitious crime story. The 'suspect' either told the true alibi immediately, or first told a false alibi and only told the true alibi during the next hearing. Half of the participants in the experiment were presented with a salacious alibi as the 'true' alibi, and the other half was presented with a non-salacious alibi. Finally, the participants also were given the reason why the suspect had initially stated a false alibi: it was either a mistake or a deliberate lie.

Nieuwkamp: 'We asked participants to determine the credibility of that alibi and compared the scores between the different groups. The result was that the credibility increased if the suspect changed his original alibi into a stay at a hotel with his lover. Better yet: if the suspect immediately stated that he was with his lover, this alibi was considered to be less credible than if first lied about. That effect was stronger than when the first alibi was false due to "a mistake".'

And all things considered, this is a new discovery: not every change in the alibi has a negative effect on its credibility, as had previously been assumed.