Table 4. Summary of the stepwise regression model with lexical tone as the dependent variable.

Age, gender, IQ, and SNPs listed in Table 2 are independent variables.

Model		Unstandardized coefficients		Standardized coefficients	t	Sig.	Adjusted R2
		B	SE	β
1	(Constant)	0.820	0.008		103.386	<0.001	0.131
	Music year	0.007	0.001	0.364	7.728	<0.001
2	(Constant)	0.633	0.053		12.013	<0.001	0.156
	Music year	0.007	0.001	0.340	7.243	<0.001
	IQ	0.002	<0.001	0.169	3.601	<0.001
3	(Constant)	0.613	0.053		11.626	<0.001	0.170
	Music year	0.007	0.001	0.328	7.015	<0.001
	IQ	0.002	<0.001	0.169	3.639	<0.001
	rs41310927	0.030	0.011	0.125	2.708	0.007