Fixed effects	Estimate	Standard error	95% CI	t	p
Mask condition (unmasked–masked)	0.23	0.02	0.20, 0.26	13.6	< 0.001
Stimuli ethnicity (black–non-black)	− 0.05	0.03	− 0.10, 0.01	− 1.6	0.134
Participant ethnicity (black–non-black)	− 0.03	0.03	− 0.09, 0.03	− 1.0	0.337
Mask * stimuli ethnicity	0.02	0.03	− 0.04, 0.09	0.7	0.472
Mask * participant ethnicity	− 0.03	0.02	-0.07, 0.01	− 1.4	0.157
Stimuli ethnicity * participant ethnicity	− 0.1	0.02	− 0.04, 0.03	− 0.3	0.789
Mask * stimuli ethnicity * participant ethnicity	− 0.1	0.04	− 0.07, 0.06	− 0.1	0.424

Random effects	Variance	SD
Participant (Intercept)	0.01	0.11
Participant| mask condition	< 0.01	0.03
Participant| stimuli ethnicity	< 0.01	< 0.01
Participant| participant ethnicity	< 0.01	0.02
Actor (Intercept)	< 0.01	< 0.01
Actor| mask condition	< 0.01	0.06
Actor| stimuli ethnicity	0.02	0.13
Actor| participant ethnicity	< 0.01	< 0.01