- Limiting the scope of potential damages. A longstanding principle in civil litigation is that the defendant “takes the plaintiff as-is.” This so-called “eggshell skull rule” generally means that the defendant is responsible for compensating the plaintiff for the full scope of the injuries for which the defendant is responsible, even if the nature of the injuries are significantly worse as a consequence of an existing infirmity in the plaintiff. At the same time, defendants are not responsible for compensating plaintiffs for injuries that already existed at the time of the accident. If the plaintiff was already dealing with a serious injury, the defendant likely will not be held responsible for the costs associated with that injury.
- Supporting or undermining arguments. A party’s personal history can raise doubts about the merits of arguments that are not adequately supported by concrete evidence. It can also help to fill in gaps in evidence to strengthen an argument. For example, a driver who left a bar and got into an accident might argue that she “hardly drinks and never drives drunk.” The plaintiff might use the plaintiff’s history of DUI convictions, reputation for alcohol abuse, or confirmed habit of drinking and driving to show that the defendant isn’t telling the truth.
- Creating or losing sympathy. Events in a person’s past can have effects on a case that are hard to quantify. Courts are often reluctant to allow evidence that serves little purpose other than to turn a jury’s opinion about a person, but as in the example of the fraud conviction, such evidence can be relevant for important reasons and have consequences beyond the narrow purpose for which it was introduced.
The backgrounds of the people involved in personal injury litigation can sometimes play a significant role in the case’s outcome. To guard against undue prejudice, courts typically won’t allow evidence or testimony about a party’s background unless it has some relevance to the case. But attorneys can find ways to make seemingly unrelated matters suddenly relevant again. For example, a decade-old conviction for fraud may not be relevant to whether a driver was responsible for a car accident, but it might be important for attacking the driver’s honesty if that is at issue. Here are a few examples of how personal history can play a role in a case.