Effects of false-evidence ploys and expert testimony on jurors, juries, and judges

Figures & data

Table 1. Means and standard deviations (in parentheses) of pre-deliberation and post-deliberation individual jurors’ deception, coercion, guilt ratings, verdicts, and sentencing recommendations as a function of false-evidence ploy (FEP) and expert presence

IV	Deception	Coercion	n, % Guilty	Guilt Ratings	Sentences
Pre-deliberation Individual Jurors
FEP Absent	7.10a (2.19)	6.30c (1.78)	146, 48.3%	5.53 (2.88)	13.80 (7.61)
FEP Present	8.28b (1.52)	6.83d (1.69)	156, 49.1%	5.70 (2.88)	13.43 (6.59)
Expert Absent	7.93e (1.83)	6.59 (1.77)	166, 56.3%g	6.17i (2.80)	14.22 (6.88)
Expert Present	7.50f (2.06)	6.55 (1.74)	136, 41.6%h	5.11j (2.86)	12.84 (7.30)
Means	7.71 (1.96)	6.57 (1.75)	302, 48.6%	5.62 (2.88)	13.61 (7.09)
Post-deliberation Individual Jurors
FEP Absent	7.22k (2.14)	6.45 (1.93)	87, 28.8%	4.62 (2.98)	9.89 (9.36)
FEP Present	8.20l (1.84)	6.93 (1.89)	97 31.0%	4.88 (3.05)	10.80 (8.15)
Expert Absent	7.92 (1.99)	6.75 (1.88)	121, 41.3%m	5.58o (3.06)	10.75 (8.08)
Expert Present	7.54 (2.09)	6.64 (1.97)	63, 19.6%n	4.00p (2.78)	9.71 (9.80)
Means	7.72 (2.05)	6.69 (1.92)	184, 29.9%	4.75 (3.02)	10.38 (8.72)

Note: Within each time of assessment (pre-deliberation or post-deliberation) and DV, values with different subscripts differ significantly, p < .05. Main effects are presented separately due to the absence of a significant interaction for any dependent measure.

Table 2. Means and standard deviations (in parentheses) of judges’ deception, coercion, guilt ratings, verdicts, and sentencing recommendations as a function of presence of FEP and presence of expert

IV	Deception	Coercion	n, % Guilty	Guilt Ratings	Sentences
FEP Absent	4.33a (2.69)	3.38 (2.11)	45, 71.4%	6.77 (2.76)	15.00 (5.86)
FEP Present	6.62b (2.01)	4.10 (2.05)	43 68.3%	6.77 (2.91)	15.33 (6.11)
Expert Absent	5.41 (2.65)	3.62 (2.17)	48, 77.4%	7.27 (2.77)	15.50 (5.90)
Expert Present	5.52 (2.63)	3.85 (2.06)	40, 62.5%	6.33 (2.82)	14.71 (6.07)
Means	5.47 (2.63)	3.74 (2.11)	88, 69.8%	6.77 (2.83)	15.16 (5.95)

Note: Deception, coercion, and guilt ratings used Likert scale (1 = not at all, 10 = completely); within each variable, means with different subscripts differ.