Jumping to Conclusions Is Associated with Paranoia but Not General Suspiciousness: A Comparison of Two Versions of the Probabilistic Reasoning Paradigm
Table 2
Comparison between high (≥2 SD) and low scorers (≤0.5 SD) on the Paranoia Checklist with respect to performance on the probabilistic reasoning tasks. Percentages, means, and standard deviations (in brackets).
Traditional variant
High scorers (n = 68)
Low scorers (n = 485)
Statistics
Draws to decision
2.65 (2.68)
3.46 (2.62)
t(551) = 2.37; P = .02
JTC (1st fish)
60%
29%
χ
2(1) = 27.18; P < .001
JTC (1st or 2nd fish)
63%
45%
χ
2(1) = 7.82; P = .005
Initial probability (after the 1st fish)
—
—
—
Decision threshold in %
—
—
—
Extended variant
High scorers (n = 68)
Low scorers (n = 449)
Statistics
Draws to decision
1.76 (2.07)
2.31 (2.28)
t(515) = 2.01; P = .047
JTC (1st fish)
81%
61%
χ
2(1) = 10.27; P = .001
JTC (1st or 2nd fish)
85%
71%
χ
2(1) = 6.40; P = .01
Initial probability (after the 1st fish)
62.95 (24.00)
69.20 (18.63)
t(497)* = 2.39; P = .05
Decision threshold in %
65.21 (24.80)
75.63 (18.42)
t(486)* = 3.94; P < .001
Note. SD: standard deviation; JTC: jumping to conclusions; *some subjects did not provide probabilistic estimates.
