. 2012 Aug 3;7(8):e41811. doi: 10.1371/journal.pone.0041811

Table 2. Hierarchical regression analyses: Variables predicting genetic vectors and number of children (in parentheses) for females (N = 54).

	model 1				model 2			model 3
variable	B	SE B	β	B		SE B	β	B	SE B	β
age	.279	.119	1.602^*	.298		.113	1.714^**	.265	.110	1.52^**
	(.311)	(.091)	(2.49)^**	(.323)		(.089)	(2.58)^**	(.295)	(.085)	(2.36)^**
age²	−002	.001	−1.080	−.002		.001	−1.144^*	−.002	.001	−.821
	(−.003)	(.001)	(−2.23)^**	(-.003)		(.001)	(−2.28)^**	(−.003)	(.001)	(−1.9)^**
fundamental frequency (Hz)				.024		.009	.285 ^**	.025	.009	.292 ^**
				(.014)		(.007)	(.236) ^*	(.015)	(.007)	(.245) ^*
handgrip strength (bars)								.075	.032	.281 ^*
								(.063)	(.025)	(.327) ^**

p<.05.

^**

p<.01 all tests are one-tailed.

Age, age² were entered as control variables. The effects of height and weight were also removed from handgrip strength before the analysis. Fundamental frequency and handgrip strength were entered as target variables (bold). Genetic vectors composes of the total number of surviving children plus the number of grandchildren (halved because of genetic relatedness), or (number of children + (.5×grandchildren)).