Table 4.

Results of the Analyses of Raw Data Sets

Study	N	Model 1: Age					Model 2: Age + Age2						Difference		U
		Int	Age	R 2	F	p	Int	Age	Age2	R 2	F	p	F	p
Chao et al. (2009)	175	−0.24	0.05	0.01	1.05	0.31	−0.47	0.16	−0.01	0.01	0.61	0.55	0.17	0.68	ns
Halfmann et al (2013)	48	−0.17	0.02	<0.01	0.11	0.74	−2.09	0.76	−0.06	0.04	1.00	0.38	1.88	0.18	ns
Hampton et al. (2018)	946	−0.13	0.04	<0.01	1.10	0.29	0.68	−0.38	0.05	<0.01	1.77	0.17	2.44	0.12	ns
Kirby et al. (2002)	516	−0.42	0.13	0.04	22.67	0.00	−0.48	0.17	<0.01	0.04	11.36	0.00	0.09	0.77	ns
Lee et al. (2018)	11157	0.21	−0.08	0.01	53.95	0.00	0.28	−0.13	0.01	0.01	27.33	0.00	0.71	0.40	ns
Lempert et al. (2018)	75	−0.73	0.10	<0.01	0.35	0.56	2.90	−0.88	0.07	0.01	0.23	0.80	0.11	0.74	ns
Li et al. (2020)	619	−0.17	0.04	<0.01	2.39	0.12	0.38	−0.24	0.03	0.01	2.84	0.06	3.28	0.07	sig
Loeckenhoff et al. (2011)	98	−0.06	0.01	<0.01	0.05	0.82	−0.42	0.17	−0.01	<0.01	0.18	0.84	0.30	0.59	ns
O’Hora et al (2016)	840	0.03	−0.01	<0.01	0.15	0.70	−0.11	0.07	−0.01	<0.01	0.24	0.79	0.32	0.57	ns
Seaman et al. (2016)	92	0.10	−0.02	<0.01	0.13	0.72	0.33	−0.13	0.01	<0.01	0.10	0.90	0.08	0.78	ns
Sisso et al. (2017)	2630	0.02	−0.01	<0.01	0.14	0.71	0.15	−0.06	0.01	<0.01	0.33	0.72	0.52	0.47	ns
Tschernegget al. (2015)	70	1.61	−0.64	0.12	9.56	0.00	−4.21	3.48	−0.69	0.21	9.11	0.00	7.71	0.01	ns

Note. Int = Intercept; U = Two-line test (Simonshon, 2018), ns = non-significant, sig = significant