What is the test for a jury to deliver a verdict in a personal injury case?

"The jury system is an institution that is legally fundamental but also fundamentally human. Jurors bring to their deliberations knowledge and beliefs about general matters of law and fact that find their source in everyday life and experience. That they do so is one of the strengths of the jury system. It is also one of its weaknesses: it has the potential to undermine determinations that should be made exclusively on the evidence introduced by the parties and the instructions given by the court. Such a weakness, however, must be tolerated. '[It] is an impossible standard to require . . . [the jury] to be a laboratory, completely sterilized and freed from any external factors.' [Citation.] Moreover, under that 'standard' few verdicts would be proof against challenge." (People v. Marshall (1990) 50 Cal.3d 907, 950.)