what does "propensity evidence" mean in a personal injury lawsuit?

Propensity evidence is evidence that a person such as the defendant in your personal injury case engaged in prior bad acts or prior bad behavior and is consequently more likely to engage in those bad acts or bad behavior again.

There are many types of such evidence. Examples.......

Bad acts that result in criminal convictions of crimes about deceit may be used in a civil case to question and taint the defendant's credibility in issue for the jury.

Prior car crashes in a car crash personal injury case may or may not be allowed depending on how similar the circumstance is to the car crash at issue.

Bad habit testimony about your defendant is of the type that often (there are exceptions) is not allowed at all in a civil case such as yours.

There are far too many examples to determine what best approach you should take.

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No one online can know what is going on in your case because online we cannot find out any details. You need a lawyer. Check with a lawyer in your locale to discuss more of the details.

Good luck to you.

God bless.

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In general there are few instances in which habit evidence can be used to show that a person acted on a particular occasion in conformity with that habit. I believe the examples quoted by my colleague are more impeachment questions than propensity. In criminal court certain kinds of propensity evidence can be used to show a character trait but the kinds have to be set forth by statute here in CA. It may be different in NY of course.

propensity evidence is often not admissible in civil cout unless it rises to the level of a "habit". Couts are interested in facts not what might have happened based on prior conduct. For example, a history of speeding tickets doesnt prove speeding at a particular moment. Habit evidence is stronger and shows hat a person always does the same thing in a given set of circumstances.