What is the test for "unduly prejudicial" evidence in a civil case?

[Citations.] 'Rather, the statute uses the word in its etymological sense of "prejudging" a person or cause on the basis of extraneous factors. [Citation.]' [Citation.]" [Citation.] In other words, evidence should be excluded as unduly prejudicial when it is of such nature as to inflame the emotions of the jury, motivating them to use the information, not to logically evaluate the point upon which it is relevant, but to reward or punish one side because of the jurors' emotional reaction. In such a circumstance, the evidence is unduly prejudicial because of the substantial likelihood the jury will use it for an illegitimate purpose.' " (People v. Doolin, supra, 45 Cal.4th at pp. 438-439.)