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The Relevance of General Causation Evidence to Jurors' Decision-making
This article discusses the second of three major factors that account for the difficulty the defense has with presenting a general causation case to a jury.
There are three major factors that account for the difficulty the defense has with presenting a general causation case to a jury. They have to do with the ways in which people process information; the relevance of general causation evidence to what the jurors care about; and the complexity of the evidence. This article will discuss the second of these strategies. We are all familiar with the idea that each side's evidence in a trial is a competing story of what happened. In a toxic tort or products case, the story lines for jurors consistently revolve around two central points. On the one hand there is the behavior of the defendant and whether it knew about, should have known, or could have known about the potential injury to the plaintiff. On the other hand, there is the plaintiff and whether he or she had any control over preventing the injury and what in the plaintiff's life experiences might be responsible for the injury. These are the two competing stories. Juries will view evidence in terms of how relevant it is to each story. That is, there is a hierarchy of evidence. Evidence that is less relevant is more likely to be discounted or forgotten. From the defense point of view, its strongest story is not the one that defends the company, but the one that focuses on the plaintiff. Testimony from epidemiologists or experts in risk assessment, while related to the plaintiff in a tangential way, is likely to be seen as pretty far down the hierarchy of relevancy. Testimony from the plaintiff is obviously at the top of the hierarchy. We have found that the hierarchy of relevancy typically continues as follows (as it relates to the issue of causation): treating physicians, experts who examined the plaintiff, experts who examined the plaintiff's medical records, experts who treat similar kinds of diseases and injuries, experts who are testifying based on the results of their research and that of others, and epidemiologists. The problem for defense lawyers is that general causation evidence is not that relevant to jurors as they build a story to help them understand the case. What can be done to improve the defense's general causation presentation? Expert testimony can be made more relevant in the following ways: 1. Have your experts examine the plaintiff, if possible, even if this is not important to their testimony. If this is not possible, have them review the plaintiff's medical records. 2. Select experts who treat patients with the injury about which the plaintiff is complaining. 3. Wherever possible, in discussing scientific studies, discuss where the plaintiff would fit in the sample and in the results (or why the plaintiff cannot be theoretically placed in the studies). 4. Normalize the plaintiff's health issues as much as possible. Show all the ways the plaintiff is similar to his or her cohort in terms of illnesses (or even in better health). 5. Both normalize and differentiate the plaintiff's life style as much as possible from his or her cohorts. That is, both show the ways in which the plaintiff is like us all in that he or she is exposed to toxic chemicals throughout his or her life; but he or she also acted in ways (or was acted upon in ways) that increased his or her risk of injury (apart, of course, from the exposure to the defendant's product). 6. Show how the plaintiff had control over the fact and extent of exposure either through knowledge he or she did, could, or should have had, or actions he or she did (or did not) or could or should have taken. This "assumption of the risk" argument is obvious, but it's opposite, described in the next point, is less so. 7. Show how the defendant had as little control as possible over the exposure (either through knowledge and/or actions). This can run counter to the tendency to want to build up the sophistication of the defense and its leading edge approaches to technology. But in the end, the defense wants the jurors to think that there was little that the defense could have done while there was a great deal that the plaintiff could have done to prevent the injury. Many of the points described above lie outside the scope of the testimony of an expert on the issue of general causation. But I hope that by now it is clear that all these points will affect the jurors' opinions about general causation. For instance, voluntary exposure to a chemical leads jurors to believe that the chemical poses a lower level of risk. This is so despite the fact that "scientifically" this makes no objective difference. Conclusion In everyday life, scientists and lawyers do not behave like scientists and lawyers. For jurors a trial is everyday life. They do not and will not reason like experts. To the lawyer and scientist, jurors may be making mistakes in their reasoning, but they are not. They are doing the reasoning of everyday life. How this is done with scientific evidence can be understood and consequently the evidence can be presented to them in a way that makes sense to everyone, lawyers, scientists, and jurors alike.