Table 2. Best LMM explaining the occurrence of yawn contagion within the first minute (AICc = −55.96).

	Numerator df	Denominator df	F	Significance level
Intercept	1	5.00	12.31	0.017
FIXED FACTORS
Trigger's gender	1	6.35	4.02	0.079
Sex combination	1	34.10	5.57	0.024
Social bonding	1	39.20	4.87	0.033
RANDOM FACTORS	Variance	SE
Trigger's identity	0.0004	0.0017
Responder's identity	0.0039	0.0031

df: degrees of freedom; SE: standard error.