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Online Supplemental Material

The Mix Matters: Complex Personal Networks Relate to Higher Cognitive Functioning in Old Age

Content

The first part of this document presents the predictive margins of cognitive functioning based on the final fixed-effects model. The second part lists additional results tables using alternative operationalizations of the predictor variable network complexity. The third part of this document presents additional results tables and figures using alternative measures of the outcome variable cognitive functioning.

Predictive margins of cognitive functioning

Table A1: Predictive margins of cognitive functioning (MMSE), depending on network complexity and time since baseline (based on Model 7 in Table 3)

Alternative measures of network complexity

Network complexity was originally measured as the number of social roles in which a respondent had bi-weekly contact with at least one person. Two alternative operationalizations of network complexity were tested, of which both deviated from the original measure only with respect to the regularity of a contact.

The first operationalization solely included very regular contacts in the index—the number of social roles in which a respondent had weekly contact with at least one person. The findings are presented in Table A2. The second operationalization included all contacts in the index—the number of social roles in which a respondent had any contact with at least one person. The findings are presented in Table A3.

Table A2: Fixed-effects models on cognitive functioning, using network complexity based on weekly contacts

Table A3: Fixed-effects models on cognitive functioning, using network complexity based on all contacts

Alternative measures of cognitive functioning

Next to the Mini-Mental State Examination (MMSE), two related measures of cognitive functioning were available in the LASA data set.

First, an adapted version of the Coding Task measured information processing speed (Savage, 1984). Participants were presented a sheet with rows of characters, and then asked to name

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the character that belonged underneath the printed characters as quickly and accurately as possible. The correct character combination was given at the top of the sheet. Every completed combination counted as one score point. There were three trials of one minute. A mean score of these three trials was computed, ranging from 1 to 50. Cronbach’s alpha was larger than 0.95 in all waves.

Second, the 15 Words Test (Saan & Deelman, 1986) assessed immediate recall and learning. The procedure involved a verbal presentation of 15 words by the interviewer. Participants were asked immediately after that to repeat these words. This was done three times. Next, participants engaged in another, non-verbal task for about 20 minutes. After this, they were asked again to recall as many of the 15 words as possible to obtain a measure of delayed recall. The score used in this analysis consisted of the number of correctly recalled words in the delayed recall test, ranging from 0 to 15.

Two sets of additional analyses were performed to investigate the association between network complexity and alternative outcomes of cognitive functioning: one set using the Coding Task as the dependent variable, and another set using the 15 Words Test as the dependent variable. Note that both the Coding Task and the 15 Words Test were not assessed among all respondents, so that the models included 2,659 individuals and a total of 8,271 observations. Models using lagged variables included 1,774 individuals, who had observations for at least two subsequent time points, and a total of 4,933 observations.

Table A4: Fixed-effects regression models on Coding Task Table A5: Predictive margins of Coding Task, depending on network complexity

and time since baseline (based on Model 7) Table A6: Fixed-effects regression models on Coding Task including lagged

variables (at t-1)

Table A7: Fixed-effects regression models on 15 Words Test Table A8: Predictive margins of 15 Words Test, depending on network

complexity and time since baseline (based on Model 7) Table A9: Fixed-effects regression models on 15 Words Test including lagged

variables (at t-1)

Figure A1: Predicted margins of Coding Task by number of social roles Figure A2: Coding Task over time, by different levels of network complexity

Figure A3: Predicted margins of 15 Words Test by number of social roles Figure A4: 15 Words Test over time, by different levels of network complexity

References

Saan, R.J. & Deelman, B.G. (1986). Nieuwe 15-woorden test A en B (15WTA en 15WTB). (New version of the 15 Words Test (15WTA en 15WTB)). In A. Bauma, J. Mulder & J. Lindeboom (Eds.), Neuro-psychologische diagnostiek: Handboek. (Neuro-psychological diagnostics: Handbook.) (pp. 13-28). Lisse: Swets & Zeitlinger Publishers.

Savage, D. (1984). Alphabet coding task. Western Australia: Murdoch University.

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Table A1

Predictive margins of cognitive functioning (MMSE), depending on network complexity and time since baseline (based on Model 7 in Table 3)

Changes in number of social rolesTime 0 1 2 3 4 5 6 7 8 9 100 years M 27.34 27.36 27.43 27.50 27.58 27.62 27.70 27.75 27.81 27.88 27.89

SD 0.15 0.16 0.16 0.16 0.15 0.15 0.14 0.14 0.12 0.14 0.113 years M 26.97 26.99 27.10 27.24 27.33 27.41 27.53 27.60 27.72 27.79 27.97

SD 0.12 0.17 0.17 0.16 0.15 0.17 0.14 0.15 0.14 0.10 0.044 years M 26.81 26.88 27.00 27.12 27.24 27.34 27.47 27.57 27.69 27.79 27.95

SD 0.13 0.17 0.17 0.16 0.16 0.18 0.17 0.16 0.19 0.14 0.126 years M 26.56 26.61 26.78 26.90 27.06 27.20 27.32 27.45 27.60 27.74 27.87

SD 0.11 0.17 0.15 0.18 0.18 0.18 0.18 0.16 0.14 0.17 0.237 years M 26.44 26.51 26.72 26.82 26.98 27.12 27.25 27.40 27.55 27.79 27.85

SD 0.15 0.17 0.18 0.17 0.19 0.19 0.17 0.22 0.19 0.19 0.309 years M 26.07 26.29 26.44 26.62 26.78 26.94 27.11 27.29 27.36 27.73 27.69

SD 0.19 0.24 0.20 0.18 0.18 0.21 0.18 0.17 0.18 0.16 0.2610 years M 25.94 26.15 26.32 26.55 26.70 26.89 27.03 27.22 27.54 27.61 n/a

SD 0.21 0.15 0.21 0.22 0.22 0.18 0.21 0.23 0.22 0.28 n/a13 years M n/a 25.72 26.05 26.17 26.41 26.60 26.81 27.02 27.24 27.42 n/a

SD n/a 0.16 0.19 0.18 0.23 0.22 0.19 0.19 0.17 0.29 n/a14 years M 25.41 25.63 25.89 26.14 26.37 26.58 26.78 27.03 27.25 27.54 27.94

SD 0.19 0.16 0.18 0.25 0.23 0.24 0.22 0.22 0.32 0.19 0.3316 years M 25.06 25.30 25.71 25.89 26.16 26.36 26.50 26.98 27.11 27.63 n/a

SD 0.14 0.21 0.27 0.19 0.21 0.19 0.19 0.41 0.25 0.43 n/a17 years M 25.18 25.29 25.54 25.81 26.05 26.35 26.58 26.91 27.11 27.46 27.70

SD 0.09 0.23 0.21 0.27 0.23 0.27 0.30 0.29 0.24 0.30 0.3419 years M n/a 24.90 25.31 25.58 25.84 26.07 26.41 26.51 27.01 n/a n/a

SD n/a 0.26 0.20 0.20 0.22 0.16 0.32 0.17 0.31 n/a n/a20 years M 24.58 24.84 25.26 25.51 25.78 26.07 26.41 26.76 26.99 27.25 n/a

SD 0.04 0.14 0.31 0.25 0.27 0.24 0.31 0.34 0.46 0.42 n/aTotal M 26.42 26.58 26.75 26.89 26.99 27.13 27.27 27.40 27.55 27.72 27.87

SD 0.82 0.77 0.67 0.63 0.59 0.49 0.44 0.37 0.33 0.27 0.24Note. n/a = not available: there were no observations.

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Table A2Fixed-effects regression models on cognitive functioning (MMSE index), using network complexity based on weekly contacts a

Model 1 Model 2 Model 3 Model 4 Model 5 Model 6 Model 7B

(CI)B

(CI)B

(CI)B

(CI)B

(CI)B

(CI)B

(CI)Controls

Time (in decades) b -0.79*** -0.78*** -0.77*** -0.77*** -0.79*** -0.78*** -0.79***

(-0.87,-0.71) (-0.86,-0.70) (-0.85,-0.69) (-0.85,-0.69) (-0.87,-0.71) (-0.86,-0.70) (-0.87,-0.71)

Partner 0.15 0.11 0.10 0.08 0.08 0.09 0.08(-0.02,0.33) (-0.06,0.29) (-0.08,0.27) (-0.09,0.26) (-0.09,0.25) (-0.09,0.26) (-0.09,0.25)

Physical functioning 0.16*** 0.15*** 0.15*** 0.15*** 0.14*** 0.14*** 0.14***

(0.08,0.24) (0.08,0.23) (0.08,0.23) (0.08,0.23) (0.06,0.21) (0.07,0.22) (0.06,0.21)

PredictorsNetwork size 0.02*** 0.02*** 0.02*** 0.02*** 0.02***

(0.02,0.03) (0.01,0.03) (0.01,0.02) (0.01,0.03) (0.01,0.02)

Network complexity weekly 0.10*** 0.07*** 0.07*** 0.06** 0.07***

(0.07,0.14) (0.03,0.11) (0.03,0.11) (0.02,0.10) (0.03,0.10)

Network size × time b 0.02*** 0.02***

(0.01,0.03) (0.01,0.03)

Network complexity weekly × time b 0.08*** 0.03(0.04,0.12) (-0.01,0.08)

Intercept 26.63*** 26.67*** 26.68*** 26.70*** 26.72*** 26.72*** 26.72***

(26.43,26.83) (26.47,26.87) (26.48,26.88) (26.50,26.89) (26.52,26.92) (26.52,26.91) (26.53,26.92)

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Nobservations 10,376 10,376 10,376 10,376 10,376 10,376 10,376Nindividuals 2,959 2,959 2,959 2,959 2,959 2,959 2,959Varobservations 1.80 1.80 1.80 1.80 1.79 1.80 1.79Varindividuals 2.87 2.83 2.84 2.82 2.84 2.83 2.84Log likelihood -19,103.14 -19,071.98 -19,043.95 -19,027.37 -19,005.50 -19,016.23 -19,004.19

Note. a Unstandardized coefficients (B) and 95% confidence intervals (CI). b Time was measured in years since baseline, divided by 10. *p < .05, **p < .01, ***p < .001.

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Table A3Fixed-effects regression models on cognitive functioning (MMSE index), using network complexity based on all contacts a

Model 1 Model 2 Model 3 Model 4 Model 5 Model 6 Model 7B

(CI)B

(CI)B

(CI)B

(CI)B

(CI)B

(CI)B

(CI)Controls

Time (in decades) b -0.79*** -0.78*** -0.77*** -0.77*** -0.79*** -0.81*** -0.81***

(-0.87,-0.71) (-0.86,-0.70) (-0.85,-0.69) (-0.85,-0.69) (-0.87,-0.71) (-0.89,-0.73) (-0.89,-0.73)

Partner 0.15 0.11 0.05 0.06 0.05 0.04 0.04(-0.02,0.33) (-0.06,0.29) (-0.12,0.22) (-0.12,0.23) (-0.12,0.23) (-0.13,0.21) (-0.13,0.21)

Physical functioning 0.16*** 0.15*** 0.15*** 0.15*** 0.14*** 0.13*** 0.13***

(0.08,0.24) (0.08,0.23) (0.08,0.23) (0.08,0.23) (0.06,0.21) (0.05,0.20) (0.05,0.20)

PredictorsNetwork size 0.02*** 0.01 0.01 0.01 0.01

(0.02,0.03) (-0.00,0.02) (-0.00,0.02) (-0.00,0.02) (-0.00,0.02)

Network complexity all 0.13*** 0.11*** 0.11*** 0.09*** 0.09***

(0.10,0.16) (0.06,0.15) (0.07,0.15) (0.05,0.13) (0.05,0.13)

Network size × time b 0.02*** 0.00(0.01,0.03) (-0.01,0.01)

Network complexity all × time b 0.13*** 0.12***

(0.10,0.16) (0.07,0.18)

Intercept 26.63*** 26.67*** 26.71*** 26.71*** 26.74*** 26.77*** 26.76***

(26.43,26.83) (26.47,26.87) (26.52,26.91) (26.52,26.91) (26.54,26.93) (26.57,26.96) (26.57,26.96)

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Nobservations 10,376 10,376 10,376 10,376 10,376 10,376 10,376Nindividuals 2,959 2,959 2,959 2,959 2,959 2,959 2,959Varobservations 1.80 1.80 1.80 1.80 1.79 1.79 1.79Varindividuals 2.87 2.83 2.81 2.80 2.82 2.84 2.84Log likelihood -19,103.14 -19,071.98 -19,019.58 -19,017.15 -18,995.53 -18,979.27 -18,979.21

Note. a Unstandardized coefficients (B) and 95% confidence intervals (CI). b Time was measured in years since baseline, divided by 10. *p < .05, **p < .01, ***p < .001.

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Table A4Fixed-effects regression models on Coding Task a

Model 1 Model 2 Model 3 Model 4 Model 5 Model 6 Model 7B

(CI)B

(CI)B

(CI)B

(CI)B

(CI)B

(CI)B

(CI)Controls

Time (in decades) b -2.86*** -2.84*** -2.82*** -2.83*** -2.86*** -2.87*** -2.88***

(-3.00,-2.71) (-2.98,-2.70) (-2.97,-2.68) (-2.97,-2.68) (-3.01,-2.72) (-3.02,-2.73) (-3.02,-2.74)

Partner -0.21 -0.26 -0.29 -0.29 -0.29 -0.30 -0.30(-0.51,0.09) (-0.56,0.04) (-0.59,0.01) (-0.59,0.01) (-0.59,0.01) (-0.59,0.00) (-0.59,0.00)

Physical functioning 0.76*** 0.75*** 0.76*** 0.75*** 0.73*** 0.72*** 0.72***

(0.63,0.90) (0.62,0.88) (0.62,0.89) (0.62,0.88) (0.60,0.86) (0.59,0.86) (0.59,0.85)

PredictorsNetwork size 0.04*** 0.03*** 0.02** 0.03*** 0.03***

(0.02,0.05) (0.01,0.04) (0.01,0.04) (0.01,0.04) (0.01,0.04)

Network complexity 0.15*** 0.09* 0.09* 0.06 0.06(0.09,0.21) (0.02,0.15) (0.02,0.16) (-0.01,0.13) (-0.01,0.13)

Network size × time b 0.03*** 0.01(0.02,0.05) (-0.00,0.03)

Network complexity × time b 0.21*** 0.17***

(0.14,0.27) (0.09,0.25)

Intercept 22.34*** 22.39*** 22.40*** 22.41*** 22.45*** 22.47*** 22.47***

(21.99,22.69) (22.04,22.74) (22.05,22.75) (22.07,22.76) (22.10,22.80) (22.12,22.81) (22.12,22.82)

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Nobservations 8,271 8,271 8,271 8,271 8,271 8,271 8,271Nindividuals 2,659 2,659 2,659 2,659 2,659 2,659 2,659Varobservations 2.81 2.80 2.80 2.80 2.79 2.79 2.79Varindividuals 7.32 7.27 7.28 7.26 7.29 7.30 7.30Log likelihood -18,668.49 -18,645.53 -18,652.32 -18,641.17 -18,623.11 -18,613.09 -18,611.11

Note. a Unstandardized coefficients (B) and 95% confidence intervals (CI). b Time was measured in years since baseline, divided by 10. *p < .05, **p < .01, ***p < .001.

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Table A5

Predictive margins of Coding Task, depending on network complexity and time since baseline (based on Model 7)

Changes in number of social rolesTime 0 1 2 3 4 5 6 7 8 9 100 years M 26.00 25.65 25.67 25.76 25.81 25.73 25.87 25.89 25.89 26.02 25.87

SD 0.76 0.73 0.71 0.69 0.66 0.69 0.63 0.61 0.63 0.60 0.563 years M 24.17 24.50 24.74 24.79 24.96 24.91 25.20 25.20 25.43 25.31 n/a

SD 0.12 0.78 0.71 0.69 0.65 0.74 0.61 0.78 0.69 0.32 n/a4 years M 24.25 24.42 24.34 24.45 24.62 24.75 24.89 25.00 25.08 25.26 25.34

SD 0.69 0.71 0.80 0.76 0.69 0.70 0.69 0.62 0.67 0.60 0.396 years M 23.71 23.45 23.65 23.72 24.01 24.21 24.31 24.48 24.72 24.55 n/a

SD 0.35 0.72 0.67 0.72 0.73 0.71 0.68 0.62 0.71 0.82 n/a7 years M 23.34 23.00 23.46 23.43 23.64 23.86 24.13 24.10 24.45 24.86 24.87

SD 0.73 0.64 0.72 0.70 0.75 0.74 0.64 0.76 0.71 0.60 1.059 years M 22.03 22.51 22.66 22.89 23.11 23.30 23.54 23.80 23.84 24.68 24.07

SD 0.63 0.86 0.81 0.74 0.66 0.76 0.66 0.61 0.73 0.54 1.2410 years M 21.92 22.04 22.26 22.64 22.73 23.10 23.28 23.45 24.16 23.97 n/a

SD 1.22 0.54 0.81 0.71 0.71 0.66 0.68 0.73 0.45 0.74 n/a13 years M n/a 20.36 21.34 21.45 21.73 22.01 22.40 22.63 23.14 23.08 n/a

SD n/a 0.64 0.71 0.71 0.85 0.76 0.68 0.67 0.68 0.90 n/a14 years M 20.81 20.43 20.85 21.26 21.55 21.84 22.21 22.52 22.78 23.44 24.08

SD 0.75 0.70 0.70 0.75 0.74 0.72 0.69 0.68 0.79 0.53 0.7016 years M 18.86 19.46 20.32 20.45 20.90 21.15 21.15 22.32 22.35 23.57 n/a

SD 0.73 0.91 0.89 0.72 0.72 0.71 0.74 0.76 0.69 0.63 n/a17 years M n/a 19.65 19.65 20.14 20.51 21.03 21.30 21.90 22.29 22.67 22.90

SD n/a 0.72 0.71 0.75 0.75 0.80 0.80 0.71 0.75 0.98 0.5619 years M n/a 18.44 19.01 19.53 19.88 20.14 20.82 20.68 21.57 n/a n/a

SD n/a 1.32 0.79 0.71 0.65 0.77 0.72 0.65 0.76 n/a n/a20 years M 17.73 17.78 18.82 19.10 19.54 20.02 20.60 21.10 21.49 21.83 n/a

SD 0.05 0.36 0.82 0.75 0.80 0.73 0.70 0.81 0.99 0.90 n/aTotal M 23.04 23.31 23.43 23.63 23.69 23.87 24.08 24.10 24.41 24.86 24.62

SD 2.45 2.41 2.24 2.17 2.11 1.88 1.80 1.67 1.58 1.50 1.25Note. n/a = not available: there were no observations.

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Table A6Fixed-effects regression models on Coding Task including lagged variables (at t-1) a

Model 1 Model 2 Model 3 Model 4B

(CI)B

(CI)B

(CI)B

(CI)Controls

Coding Task at t-1 0.01 0.00 0.00 0.00(-0.03,0.05) (-0.03,0.04) (-0.04,0.04) (-0.04,0.04)

Time (in decades) b -3.79*** -3.73*** -3.73*** -3.70***

(-4.07,-3.52) (-4.00,-3.45) (-4.01,-3.46) (-3.98,-3.43)

Partner -0.51* -0.60** -0.61** -0.63**

(-0.93,-0.09) (-1.02,-0.17) (-1.03,-0.19) (-1.05,-0.20)

Physical functioning 0.56*** 0.56*** 0.57*** 0.57***

(0.37,0.75) (0.37,0.75) (0.38,0.76) (0.38,0.76)

PredictorsNetwork size 0.04*** 0.04***

(0.03,0.06) (0.02,0.06)

Network size at t-1 0.01 0.01(-0.00,0.03) (-0.01,0.03)

Network complexity 0.15*** 0.08(0.07,0.23) (-0.02,0.17)

Network complexity at t-1 0.09* 0.07(0.01,0.17) (-0.02,0.17)

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Intercept 23.80*** 23.90*** 23.98*** 23.97***

(22.69,24.92) (22.79,25.01) (22.86,25.09) (22.86,25.08)Nobservations 4,933 4,933 4,933 4,933Nindividuals 1,774 1,774 1,774 1,774Varobservations 2.76 2.75 2.76 2.75Varindividuals 7.43 7.36 7.39 7.35Log likelihood -10,907.44 -10,889.66 -10,895.69 -10,886.28

Note. a Unstandardized coefficients (B) and 95% confidence intervals (CI). b Time was measured in years since baseline, divided by 10. *p < .05, **p < .01, ***p < .001.

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Table A7Fixed-effects regression models on 15 Words Test a

Model 1 Model 2 Model 3 Model 4 Model 5 Model 6 Model 7B

(CI)B

(CI)B

(CI)B

(CI)B

(CI)B

(CI)B

(CI)Controls

Time (in decades) b -0.64*** -0.63*** -0.62*** -0.62*** -0.63*** -0.64*** -0.64***

(-0.73,-0.54) (-0.73,-0.54) (-0.72,-0.53) (-0.72,-0.53) (-0.73,-0.54) (-0.74,-0.54) (-0.74,-0.54)

Partner 0.06 0.04 0.03 0.02 0.02 0.02 0.02(-0.14,0.26) (-0.16,0.24) (-0.18,0.23) (-0.18,0.23) (-0.18,0.23) (-0.18,0.23) (-0.18,0.23)

Physical functioning 0.24*** 0.24*** 0.24*** 0.23*** 0.23*** 0.23*** 0.23***

(0.15,0.33) (0.14,0.33) (0.15,0.33) (0.14,0.33) (0.14,0.32) (0.13,0.32) (0.13,0.32)

PredictorsNetwork size 0.02*** 0.01* 0.01 0.01* 0.01*

(0.01,0.02) (0.00,0.02) (-0.00,0.02) (0.00,0.02) (0.00,0.02)

Network complexity 0.07** 0.04 0.04 0.03 0.03(0.03,0.11) (-0.00,0.09) (-0.00,0.09) (-0.01,0.08) (-0.01,0.08)

Network size × time b 0.01 -0.00(-0.00,0.02) (-0.01,0.01)

Network complexity × time b 0.08*** 0.08**

(0.03,0.12) (0.02,0.13)

Intercept 4.97*** 4.99*** 5.00*** 5.01*** 5.01*** 5.02*** 5.02***

(4.74,5.21) (4.76,5.23) (4.76,5.24) (4.77,5.24) (4.78,5.25) (4.79,5.26) (4.79,5.26)

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Nobservations 8,271 8,271 8,271 8,271 8,271 8,271 8,271Nindividuals 2,659 2,659 2,659 2,659 2,659 2,659 2,659Varobservations 1.90 1.89 1.89 1.89 1.89 1.89 1.89Varindividuals 2.67 2.65 2.65 2.64 2.65 2.65 2.65Log likelihood -15,420.09 -15,411.26 -15,412.47 -15,408.73 -15,405.95 -15,400.38 -15,400.38

Note. a Unstandardized coefficients (B) and 95% confidence intervals (CI). b Time was measured in years since baseline, divided by 10. *p < .05, **p < .01, ***p < .001.

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Table A8

Predictive margins of 15 Words Test, depending on network complexity and time since baseline (based on Model 7)

Changes in number of social rolesTime 0 1 2 3 4 5 6 7 8 9 100 years M 5.89 5.84 5.87 5.92 5.96 5.96 6.03 6.05 6.07 6.13 6.09

SD 0.24 0.25 0.24 0.24 0.23 0.24 0.22 0.22 0.21 0.23 0.193 years M 5.38 5.53 5.63 5.69 5.76 5.77 5.89 5.93 6.02 5.97 n/a

SD 0.05 0.26 0.24 0.24 0.22 0.25 0.20 0.25 0.23 0.15 n/a4 years M 5.43 5.52 5.53 5.60 5.69 5.75 5.83 5.88 5.92 6.04 6.06

SD 0.21 0.24 0.26 0.25 0.23 0.24 0.24 0.22 0.24 0.21 0.176 years M 5.31 5.27 5.36 5.42 5.54 5.63 5.69 5.77 5.88 5.82 n/a

SD 0.11 0.22 0.21 0.24 0.25 0.24 0.22 0.21 0.22 0.25 n/a7 years M 5.21 5.15 5.34 5.36 5.46 5.55 5.66 5.68 5.82 6.00 6.04

SD 0.23 0.22 0.24 0.23 0.25 0.25 0.21 0.26 0.24 0.20 0.379 years M 4.86 5.06 5.12 5.24 5.34 5.43 5.53 5.65 5.68 5.98 5.78

SD 0.24 0.31 0.27 0.24 0.22 0.25 0.22 0.20 0.23 0.14 0.4710 years M 4.82 4.94 5.01 5.18 5.25 5.40 5.48 5.57 5.83 5.79 n/a

SD 0.38 0.19 0.26 0.24 0.24 0.22 0.23 0.24 0.16 0.23 n/a13 years M n/a 4.48 4.81 4.87 5.00 5.13 5.29 5.40 5.57 5.63 n/a

SD n/a 0.20 0.23 0.24 0.27 0.25 0.23 0.21 0.20 0.28 n/a14 years M 4.56 4.50 4.68 4.84 4.98 5.11 5.25 5.40 5.50 5.74 5.98

SD 0.23 0.23 0.23 0.25 0.24 0.23 0.22 0.21 0.26 0.17 0.1916 years M 3.99 4.21 4.59 4.63 4.82 4.96 4.96 5.38 5.41 5.83 n/a

SD 0.22 0.28 0.28 0.25 0.24 0.22 0.24 0.24 0.23 0.18 n/a17 years M n/a 4.33 4.36 4.57 4.72 4.93 5.05 5.28 5.43 5.60 5.70

SD n/a 0.24 0.23 0.25 0.23 0.25 0.24 0.22 0.22 0.29 0.1919 years M n/a 4.02 4.22 4.44 4.57 4.72 4.97 4.88 5.31 n/a n/a

SD n/a 0.50 0.25 0.28 0.21 0.24 0.24 0.20 0.22 n/a n/a20 years M 3.72 3.81 4.16 4.30 4.50 4.69 4.92 5.10 5.27 5.41 n/a

SD 0.02 0.09 0.27 0.23 0.25 0.22 0.24 0.25 0.30 0.25 n/aTotal M 5.12 5.24 5.32 5.41 5.47 5.55 5.65 5.70 5.81 5.92 5.98

SD 0.65 0.63 0.58 0.55 0.52 0.45 0.42 0.38 0.34 0.31 0.26Note. n/a = not available: there were no observations.

THE MIX MATTERS 16

Table A9Fixed-effects regression models on 15 Words Test including lagged variables (at t-1) a

Model 1 Model 2 Model 3 Model 4B

(CI)B

(CI)B

(CI)B

(CI)Controls

15 Words Test at t-1 -0.13*** -0.13*** -0.13*** -0.13***

(-0.16,-0.09) (-0.16,-0.09) (-0.16,-0.09) (-0.16,-0.09)

Time (in decades) b -1.69*** -1.67*** -1.68*** -1.67***

(-1.86,-1.52) (-1.84,-1.50) (-1.85,-1.51) (-1.84,-1.50)

Partner -0.12 -0.14 -0.13 -0.14(-0.40,0.15) (-0.42,0.13) (-0.41,0.14) (-0.42,0.14)

Physical functioning 0.12* 0.12* 0.13* 0.12*

(0.00,0.25) (0.00,0.25) (0.00,0.25) (0.00,0.25)

PredictorsNetwork size 0.01 0.01

(-0.00,0.02) (-0.00,0.02)

Network size at t-1 0.00 0.00(-0.01,0.02) (-0.01,0.01)

Network complexity 0.02 -0.00(-0.04,0.07) (-0.06,0.06)

Network complexity at t-1 0.02 0.02(-0.03,0.08) (-0.04,0.08)

THE MIX MATTERS 17

Intercept 6.79*** 6.80*** 6.80*** 6.79***

(6.39,7.20) (6.39,7.20) (6.39,7.20) (6.39,7.20)Nobservations 4,933 4,933 4,933 4,933Nindividuals 1,774 1,774 1,774 1,774Varobservations 1.80 1.80 1.80 1.80Varindividuals 3.21 3.19 3.20 3.19Log likelihood -8,795.15 -8,792.97 -8,794.33 -8,792.64

Note. a Unstandardized coefficients (B) and 95% confidence intervals (CI). b Time was measured in years since baseline, divided by 10. *p < .05, **p < .01, ***p < .001.

THE MIX MATTERS 18

Figure A1

Predicted margins of changes in Coding Task by changes in number of social roles22

.523

23.5

2424

.525

Cod

ing

Task

0 1 2 3 4 5 6 7 8 9 10Number of social roles

Note. a Estimates base on the full fixed-effects model (Model 7).

THE MIX MATTERS 19

Figure A2

Changes in Coding Task over time, by different levels of network complexity a18

2022

2426

Cod

ing

Task

0 5 10 15 20Years since baseline

Very high (+2 SD)High (+1 SD)Average (M)Low (-1 SD)Very low (-2 SD)

Network complexity

Note. a Respondents were grouped into those with average level of network complexity (mean), very high (+2 standard deviation), high (+1 standard deviation), low (-1 standard deviation) and very low (-2 standard deviation) level of network complexity.

THE MIX MATTERS 20

Figure A3

Predicted margins of changes in 15 Words Test by changes in number of social roles5

5.5

66.

515

Wor

ds T

est

0 1 2 3 4 5 6 7 8 9 10Number of social roles

Note. a Estimates base on the full fixed-effects model (Model 7).

THE MIX MATTERS 21

Figure A4

Changes in 15 Words Test over time, by different levels of network complexity a3.

54

4.5

55.

515

Wor

ds T

est

0 5 10 15 20Years since baseline

Very high (+2 SD)High (+1 SD)Average (M)Low (-1 SD)Very low (-2 SD)

Network complexity

Note. a Respondents were grouped into those with average level of network complexity (mean), very high (+2 standard deviation), high (+1 standard deviation), low (-1 standard deviation) and very low (-2 standard deviation) level of network complexity.