Fig. 5: Effects of mask policy on paranoia and belief updating.
From: Paranoia and belief updating during the COVID-19 crisis
We observed a significant increase in paranoia and perceived volatility, especially in states that issued a state-wide mask mandate. a, Map of the US states colour-coded to their respective mask policy (nrec = 40, nreq = 11) and a DiD analysis (bottom: n = 533, δDiD = 0.396, P = 0.038) of mask rules suggested a 40% increase in paranoia in states that mandated mask-wearing. b, Win-switch rate (left: n = 172, nrec = 120, nreq = 52, t67 = −2.4, P = 0.039, Cohen’s d = 0.483, 95% CI = −0.164 to −0.015) and volatility belief (middle: t141 = −3.7, P < 0.001, Cohen’s d = −3.739, 95% CI = 0 to −1.585) were higher in mask-mandating states but more protests per day occurred in mask-recommended states (right: n = 110, nrec = 55, nreq = 55, t83 = 3.10, P = 0.0027, Cohen’s d = 0.591, 95% CI = 17.458–80.142). c, Effects of CTL in mask-recommended states (left; n = 120, nloose = 38, ntight = 82, t57 = 3.06, P = 0.003, Cohen’s d = 0.663, 95% CI = 0.022–0.107) and mask-required states (right; n = 52, nloose = 48, ntight = 4 (t47 = 12.84, P < 0.001, Cohen’s d = 1.911, 95% CI = 0.064–0.088) implicating violation of social norms in the genesis of paranoia. d, Follow-up study (n = 405, nlow = 314, nhigh = 91) illustrating that participants with high paranoia are less inclined to wear masks in public (left: t158 = 4.59, P < 0.001, Cohen’s d = 0.520, 95% CI = 0.091–0.229), have more promiscuous switching behaviour (middle: t138 = −6.40, P < 0.001, Cohen’s d = 1.148, 95% CI = −0.227 to −0.120) and elevated prior beliefs about volatility (right: t138 = −6.04, P < 0.001, Cohen’s d = −6.041, 95% CI = 0 to −2.067). In b and d, the centre horizontal lines within the plots represent the median values, the boxes span from the 25th to the 75th percentile and the whiskers extend to 1.5× the interquartile range.
