Dateline: July, 2022, Issue 1

Do jurors distinguish illustrative and substantive demonstratives when awarding damages?

Evidence can be presented to jurors both verbally and visually, and if visual, as either an illustrative or substantative demonstrative. A substantive demonstrative has independent probative force, providing independent proof of a fact at issue in the case. Illustrative aids give visual form to other evidence, but provide no independent proof of that other evidence.


Park and Feigenson (2021) conducted three studies that examined the effects of demonstrative evidence on mock jurors' pain and suffering damage awards. In each study, the jurors read excerpts from an actual LASIK malpractice case involving a plaintiff who underwent corrective surgery despite having a prior condition in his corneas that the LASIK surgeon negligently failed to detect.

In this research, jurors were provided a summary of case facts followed by excerpts of trial testimony from both the plaintiff and the plaintiff's expert ophthalmologist.

Additionally, one group of jurors was provided substantive demonstratives of photographic simulations of the plaintiff's impaired vision (testified to be made by computerized wavefront technology which measures and plots distortions in vision). Another group of jurors was provided the identical photographic simulations as illustrative demonstratives (said to be created in Photoshop in accord with described symptoms). A third group of jurors received no demonstrative evidence. Jurors then received instructions from the judge that included the evidentiary status of demonstratives as substantive or illustrative, respectively.

Jurors also were told the defendant had previously been found negligent with compensatory damages of $100,000 already awarded, and that their task was to reach a decision about the amount of damages, if any, for the plaintiff's pain and suffering.


In all 3 studies, exposing jurors to photo simulations of a plaintiff's visual impairments significantly increased damage awards for the plaintiff's pain and suffering. Regardless whether the demonstrative was illustrative or substantive, jurors who saw demonstrative evidence awarded significantly higher damages for pain and suffering than did jurors who did not see demonstrative evidence.

Jurors presented the photos as substantive evidence thought those photos were more accurate depictions of the plaintiff's eyesight, better captured the plaintiff's impairments, and better enabled them to see things from the plaintiff's point of view than did jurors exposed to the identical photos presented as mere illustrative aids.

Despite jurors noting these differences between substantive and illustrative photos, the distinction between illustrative and substantive demonstratives did not, on the whole, significantly affect jurors' damage awards for the plaintiff's pain and suffering. In 2 of the 3 studies, and in aggregated data across the 3 studies, jurors awarded the plaintiff the same amount of damages regardless of the evidentiary status of the images they saw. One anomalous result occurred in the third study where the photos presented as substantive evidence generated higher damage awards than when presented as illustrative evidence.

Photo simulations of the plaintiff's visual impairments increased jurors' damage awards because the demonstratives led jurors to evaluate the plaintiff's suffering as more severe. Jurors presented photos as illustrative aids judged the plaintiff's visual impairment to be as severe as jurors presented the identical photos as substantive evidence.

The results pertaining to similar damage awards and similar perceptions of injury severity for illustrative and substantive demonstratives occurred despite overwhelming reports by the jurors who were presented the photos as illustrative aids saying that they had used the pictures only as illustrative evidence (85% in Study 1; 78% in Study 2; 62% in Study 3).

The researchers also found that it did not matter who presented the demonstrative (plaintiff or expert witness) or whether the plaintiff's credibility was high or low. Across these variations, demoonstrative evidence, both illustrative and substantive, similarly increased jurors' pain and suffering damage awards.


Jurors differentiate substantive from illustrative evidence, but do not consistently award the plaintiff different amounts of damages for pain and suffering based on its evidentiary status. For the most part, jurors award damages regadless of the evidentiary status of demonstratives.

What appears to matter most is whether demonstratives are used at all, not whether they are admitted as substantive or illustrative.

SourcePark, J. & Feigenson, N.R. (2021). Picturing pain and suffering: Effects of demonstrative evidence, instructions, and plaintiff credibility on mock jurors' damage awards. Applied Cognitive Psychology, 35(3), pp. 730-750.