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. 2015 Apr 6;10(4):e0121554. doi: 10.1371/journal.pone.0121554

Table 8. Results of Study 2.

Coefficient z SE P
Fixed effects
Level 1
Intercept 3.82 48.85 0.08 <.001
H it -0.47 -10.95 0.04 <.001
I 1it 0.14 1.80 0.08 .075
I 2it 0.04 0.29 0.12 .773
H it I 1it 0.08 2.65 0.03 .009
H it I 2it 0.14 3.44 0.04 .001
Level 2
S t 0.14 1.11 0.12 .269
A t 0.02 2.80 0.01 .007
S t A t -0.01 -0.91 0.01 .366
Cross-level
H it S t 0.01 0.21 0.01 .837
I 1it S t -0.04 -0.31 0.12 .758
I 2it S t 0.08 0.44 0.18 .663
H it I 1it S t -0.05 -1.10 0.04 .273
H it I 2it S t -0.06 -1.26 0.05 .212
H it A t <-.01 -0.48 < .01 .632
I 1it A t -0.01 -1.40 0.01 .168
I 2it A t -0.01 -1.15 0.01 .261
H it I 1it A t < .01 0.99 < .01 .326
H it I 2it A t < .01 0.88 0.01 .379
H it S t A t < .01 0.63 0.01 .534
I 1it S t A t -0.01 -0.75 0.01 .457
I 2it S t A t -0.02 -1.02 0.02 .312
H it I 1it S t A t -0.01 -1.66 0.01 .100
H it I 2it S t A t -0.01 -2.30 0.01 .023
Random effects
s 2(ε it) 2.17 90.95 0.02 <.001
s 2(υ 0t) 0.45 7.35 0.06 <.001
s 2(υ 1t) 0.11 6.82 0.02 <.001
s 2(υ 2t) 0.38 6.11 0.06 <.001
s 2(υ 3t) 0.98 7.44 0.14 <.001
s 2(υ 4t) 0.02 2.00 0.01 .006
s 2(υ 5t) 0.04 3.37 0.01 .022
s(υ 0t, υ 1t) 0.05 2.08 0.02 .037
s(υ 0t, υ 2t) -0.14 -2.97 0.05 .003
s(υ 0t, υ 3t) -0.37 -5.03 0.07 <.001
s(υ 0t, υ 4t) -0.02 -0.92 0.02 .359
s(υ 0t, υ 5t) -0.01 -0.34 0.02 .734
s(υ 1t, υ 2t) -0.07 -3.21 0.02 .001
s(υ 1t, υ 3t) -0.02 -0.53 0.03 .599
s(υ 1t, υ 4t) -0.03 -2.95 0.01 .003
s(υ 1t, υ 5t) -0.01 -0.97 0.01 .332
s(υ 2t, υ 3t) 0.07 1.09 0.06 .278
s(υ 2t, υ 4t) 0.01 0.38 0.02 .706
s(υ 2t, υ 5t) 0.01 0.28 0.02 .783
s(υ 3t, υ 4t) -0.02 -0.65 0.03 .515
s(υ 3t, υ 4t) <-.01 -0.06 0.03 .955
s(υ 4t, υ 5t) <-.01 -0.07 0.01 .948

I 1it and I 2it are Indicator or Dummy variables indicating the stimulus category (I 1it: 1 = African infants, 0 = Caucasian infants; I 1it: 1 = dog puppies, 0 = Caucasian infants). H it reflects the health state (0 = mean assessment of perceived health across all stimuli and participants, a positive value indicates perceived above-average illness frequency). S t represents participants’ sex (0 = male, 1 = female). A t indicates participants’ age (0 = mean age of the sample). For interpreting the coefficients all other predictor variables have to be held constant.

An unstructured covariance structure was used for the random part at Level 2. Hence, the variances and covariances of Level 2 residuals were estimated without any constraints. Robust estimators were used for statistical inference with respect to fixed effects and variance components to account for possible violations of model assumptions, such as normality of Level-2 residuals. Degrees of freedom were computed based on the Satterthwaite’s Approximation to account for the moderate sample size at Level 2 [46]. Therefore, the degrees of freedom were not necessarily integers and could vary across tests independent of the number of parameters.