. 2022 Jun 30;12:11025. doi: 10.1038/s41598-022-15208-4

Table 5.

Pearson correlations between whole brain complexity and general intelligence g and correlation comparison between sexes; where r is the correlation coefficient; **correlation is significant at the .01 level (2-tailed), *correlation is significant at .05 level (2-tailed), the probability p < .05 is uncorrected; test statistic z for correlation comparison (First transformed the r to Z using the Fisher Z transformations so that they were normally distributed and then applied a Z test where the differences in the Z measured was divided by the standard error. A Z score of greater than ± 1.96 was considered significant), and t statistic for the slope difference.

Correlation between general intelligence g and whole brain complexity	All	Women	Men	Correlation comparison (Women and Men)	Slope comparison (Women and Men)
Mysore Parthenon Cohort Correlation between general intelligence g and brain complexity at age 20–22	r = .160* p = .040 N = 166	r = .291 p = .009 N = 80**	r = .184 p = .089 N = 86	z = .718 p = .237	t = .682 p = .495
ACONF Correlation between childhood general intelligence g^a and brain complexity at age 60–66	r = .154* p = .017 N = 238	r = .361 p < .001 N = 122**	r = .094 p = .318 N = 116	z = 2.16 p = .015	t = 3.027 p = .003
ACONF Correlation between general intelligence g at age 60–66 and brain complexity at the same age (60–66)	r = .099 p = .127 N = 238	r = .270 p = .003 N = 122**	r = .098 p = .296 N = 116	z = 1.36 p = .086	t = 1.898 p = .059
UK Biobank Correlation between general intelligence g and brain complexity at age 60–66^b	r = .154 p < .001 N = 1969**	r = .174 p < .001 N = 1062**	r = .083* p = .012 N = 907	z = 2.045 p = .021	t = 2.060 p = .040
UK Biobank Correlation between general intelligence g and brain complexity at age 45–79	r = .141 p < .001 N = 6659**	r = .153 p < .001 N = 3505**	r = .101 p < .001 N = 3154**	z = 2.153 p = .016	t = 2.120 p = .034

Correlation between general intelligence g and whole brain complexity

All

Women

Men

Correlation comparison (Women and Men)

Slope
comparison
(Women and
Men)

Mysore Parthenon Cohort

Correlation between general intelligence g and brain complexity at age 20–22

r = .160*

p = .040

N = 166

r = .291**

p = .009

N = 80

r = .184

p = .089

N = 86

z = .718

p = .237

t = .682

p = .495

ACONF

Correlation between childhood general intelligence g^a and brain complexity at age 60–66

r = .154*

p = .017

N = 238

r = .361**

p < .001

N = 122

r = .094

p = .318

N = 116

z = 2.16

p = .015

t = 3.027

p = .003

ACONF

Correlation between general intelligence g at age 60–66 and brain complexity at the same age (60–66)

r = .099

p = .127

N = 238

r = .270**

p = .003

N = 122

r = .098

p = .296

N = 116

z = 1.36

p = .086

t = 1.898

p = .059

UK Biobank

Correlation between general intelligence g and brain complexity at age 60–66^b

r = .154**

p < .001

N = 1969

r = .174**

p < .001

N = 1062

r = .083*

p = .012

N = 907

z = 2.045

p = .021

t = 2.060

p = .040

UK Biobank

Correlation between general intelligence g and brain complexity at age 45–79

r = .141**

p < .001

N = 6659

r = .153**

p < .001

N = 3505

r = .101**

p < .001

N = 3154

z = 2.153

p = .016

t = 2.120

p = .034

The significant values are shown in bold.

^aChildhood general intelligence g data are not contemporaneous with MRI acquisition as for the rest of data.

^b The UK Biobank group 60–66 y was retrieved from the UK Biobank data (45–79 y) in order to match the ACONF age group for a better comparison with an increased number of participants.