Alibis: To Believe or Not to Believe3
A point that I found interesting from this study that has been demonstrated in other studies and real life, is the fact that the more confident the eyewitness is, the more likely the jurors are to convict. Why is the testimony of an eyewitness necessarily better than the alibi of the defendant? An alibi may be fabricated to protect the defendant, but eyewitness testimony could also be fabricated to convict the defendant. Also, memory is not as fail-safe as we believe it to be, as I will illustrate later on in the paper.
So far, in past research, we have found that a person who is a relative of the defendant or who has a close personal relationship with the defendant does not impact the juror’s decision. The juror will most likely still find the defendant guilty regardless of the presence of an alibi, assuming the corroborator is a close friend or relative. These findings were again replicated in a study done by Elizabeth Olson and Gary Wells.
The Olson and Wells study (2004) was intended to be a little more elementary so as to gain a basic background understanding of alibis.
To run the study, Olson and Wells manipulated physical evidence into three levels: none, easy to fabricate, and difficult to fabricate. They manipulated person evidence into four levels: none, motivated familiar other (ex: relative), non-motivated familiar other (ex: neighbor), and non-motivated stranger (ex: store clerk). It was hypothesized that physical and person evidence would have main effects on believability and it was expected that levels of person evidence would not have an impact on the highest level of physical evidence (see Table 2 of the Appendix).
The participants for the study were 252 students from a Midwestern university. Participants were asked to read a crime scenario
and then evaluate three different alibis for three different suspects as if they were detectives. In each of the alibis, person evidence and physical evidence were manipulated, with believability being the main factor being evaluated. After reading each alibi, the participants were asked to rate each one on an 11-point scale with 0=do not believe at all, and 10=completely believe.
An ANOVA analysis of the data showed a significant interaction between physical evidence and person evidence on how believable evaluators rated alibis. A significant main effect was also found for physical evidence. The results showed that the type of person evidence that was presented only affected the alibi believability when there was no physical evidence. Also, alibi providers with easily fabricated physical evidence were rated significantly less likely to be the gunman than those with no physical evidence. Alibi providers with difficult-to-fabricate physical evidence were rated significantly less likely to be the gunman than those with no physical evidence. Their findings basically replicated those of Culhane and Hosch (2004), however they were surprised to find that easy to fabricate evidence was enough to completely make the person evidence irrelevant (Olson and Wells, 2004). I feel that this study was a great addition to the alibi literature. It provided us with a general idea of how people view certain aspects of an alibi, and whether or not, according to these aspects, they believe the alibi.
Olson and Wells Taxonomy
Easy to Fabricate
Difficult to Fabricate
Motivated Familiar Other
(easy to fabricate, not likely mistaken)
WSU Psychology Student Journal, Issue ASarah Shurbert