Upload
collin
View
40
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Genetic simplex modeling of personality in adolescent Australian twins. N.A. GILLESPIE 1 , D. M. EVANS 1 , N.G. MARTIN 1. 1 Queensland Institute of Medical Research and University of Queensland, Joint Genetics Program, Brisbane, Australia. - PowerPoint PPT Presentation
Citation preview
Genetic simplex modeling of personality in adolescent Australian twins
N.A. GILLESPIE1, D. M. EVANS1, N.G. MARTIN1
1Queensland Institute of Medical Research and University of Queensland, Joint Genetics Program, Brisbane, Australia.
Supported by Queensland Cancer Fund, Cooperative Research Centre for Discovery of Genes for Common Human Diseases, and NHMRC grants 901061 & 9050998.
Modeling personality change
Eaves, Eysenck & Martin (1989)
Adult personality - High of genetic continuity over time !
Effect stronger in Neuroticism vs Extraversion
Genetic continuity in adolescents?
Simplex modeling (Boomsma, 1989)
Genetic Simplex modeling
Autoregressive model
Structural equation model
ηi = βi ηi-1 + ζi
var (ηi) = βi2 var (ηi-1) + var (ζi)
ζ i-1
i-1
Yi-1Yi Yi+1
ζ i ζ i+1
λ i-1 λ i λ i+1ε i-1
β iβ i+1i i+1
ε i ε i+1
Measurement model
Yi = λi ηi + εi
var (Yi) = λi2 var (ηi) + var (εi)
TWIN 1 TWIN 2
1 1 1
E11
ζE11 ζE12 ζE13
βE2βE3
ζA12 ζA13
Y11Y12 Y13
ε11 ε12 ε13
ζA11
A11
11 1
βA2 βA3
1 1 1
ζE21 ζE22 ζE23
βE2βE3
ζA22 ζA23
ε21 ε22 ε23
ζA21
11 1
βA2 βA3
Y21Y22 Y23
A12 A13 A23 A23A23
E12 E23E22E21E13
Sample
Twin Mole and Twin MAPS projects
Assess the genetic / environmental etiology of Melanocytic Naevi (common moles) in twins aged 12 & 14 years + Cognition at 16
81 items JEPQ - Psychoticism (P) - Extraversion (E) - Neuroticism (N) - Lie (L)
Twin Mole Twin MAPS12 yrs 14 yrs 16 yrs
P E N L P E N L P E N L
Male 603 604 606 605 465 466 466 467 416 412 416 415
Female 605 602 607 609 471 470 473 473 442 438 442 442
Data
Normal weighted by sex and age
Structural equation modeling using ML analysis of individual observations performed in Mx
Raw continuous data methods
Assumptions of mean and variance homogeneity by twin order and zygosity (and necessarily by sex and age)
Polychoric test-retest correlations
P 12 14 16
12 -14 .55 -16 .45 .55 -
N=505
E 12 14 16
12 -14 .58 -16 .51 .67 -
N=498
N 12 14 16
12 -14 .58 -16 .48 .64 -
N=509
L 12 14 16
12 -14 .57 -16 .47 .63 -
N=510
Twin pair polychoric correlations
Consistent with a genetic hypothesis !
Univariate & Multivariate results
AE best fitting model
Model -2LL df 2LL df p AIC
1. 7630.37 2991 0.00 5 5 -10.00
P12 P14 P16
ε1 ε2 ε3
ζA2 ζA3
1 1 1
E1
ζE1 ζE2 ζE3
βE2βE3
E2 E3
ζA1
11 1
βA2 βA3A1 A2 A3
Psychoticism
AE Simplex model
ζA2
1 1 1
E1
ζE1 ζE2 ζE3
βE2βE3
E2 E3
ζA1
11 1
βA2 βA3A1 A2 A3
Psychoticism
Drop genetic innovation @ 16 years
P12 P14 P16
ε1 ε2 ε3
Model -2LL df 2LL df p AIC
1. 7630.37 2991 0.00 5 5 -10.00
2. 7635.80 2992 5.43 1 * 3.43
ζA3
1 1 1
E1
ζE1 ζE2 ζE3
βE2βE3
E2 E3
ζA1
11 1
βA2 βA3A1 A2 A3
Psychoticism
Drop genetic innovation @ 14 years
P12 P14 P16
ε1 ε2 ε3
Model -2LL df 2LL df p AIC
1. 7630.37 2991 0.00 5 5 -10.00
2. 7635.80 2992 5.43 1 * 3.43
3. 7634.82 2992 4.45 1 * 2.45
Psychoticism - Best fitting Simplex model
TimeζA /
Var(ηA)ζE /
Var(ηE)
14 .27 .55
16 .37 .25
ε1
.36
.93
.55 1.15
P12
A1
E1
P14
A2
E2
P16
A3
E3
ε1
.36ε1
.36
ζA2
.12ζA1
.37ζA3
.13
.70
ζE1
.15
ζE2
.06
ζE3
.05
1 1 1
1 1 1
Extraversion
AE Simplex model
Model -2LL df 2LL df p AIC
1. 7538.80 2981 0.00E12 E14 E16
ε1 ε2 ε3
ζA2 ζA3
1 1 1
E1
ζE1 ζE2 ζE3
βE2βE3
E2 E3
ζA1
11 1
βA2 βA3A1 A2 A3
Extraversion
Drop genetic innovation @ 16 years
E12 E14 E16
ε1 ε2 ε3
ζA2
1 1 1
E1
ζE1 ζE2 ζE3
βE2βE3
E2 E3
ζA1
11 1
βA2 βA3A1 A2 A3Model -2LL df 2LL df p AIC
1. 7538.80 2981
2. 7538.96 2982 0.16 1 .69 -1.84
Extraversion
Drop genetic innovation @ 14 years
E12 E14 E16
ε1 ε2 ε3
ζA3
1 1 1
E1
ζE1 ζE2 ζE3
βE2βE3
E2 E3
ζA1
11 1
βA2 βA3A1 A2 A3Model -2LL df 2LL df p AIC
1. 7538.80 2981
2. 7538.96 2982 0.16 1 .69 -1.84
3. 7544.34 2982 5.54 1 * 3.54
Extraversion - Best fitting Simplex model
ε1
.23
.92
.53 .72
E12
A1
E1
E14
A2
E2
E16
A3
E3
ε1
.23ε1
.23
ζA2
.12ζA1
.38
.93
ζE1
.35
ζE2
.18
ζE3
.17
1 1 1
1 1 1
TimeζA /
Var(ηA)ζE /
Var(ηE)
14 .27 .64
16 .00 .53
Time Var(η A1-3 ) Var(η E1-3 )Var(ε) Total
E12 .38 .35 .23 .96
E14 .922 .38 + .12= .44 .532 .35 + 18 = .28 .23 1.00
E16 .932 .44 + .00 = .38 .722 .28 + .17 = .32 .23 .93
N12 N14 N16
ε1 ε2 ε3
ζA2 ζA3
1 1 1
E1
ζE1 ζE2 ζE3
βE2βE3
E2 E3
ζA1
11 1
βA2 βA3A1 A2 A3Model -2LL df 2LL df p AIC
1. 7724.22 2999 2.26 5 .81 -7.74
Neuroticism
AE Simplex model
N12 N14 N16
ε1 ε2 ε3
ζA2
1 1 1
E1
ζE1 ζE2 ζE3
βE2βE3
E2 E3
ζA1
11 1
βA2 βA3A1 A2 A3Model -2LL df 2LL df p AIC
1. 7724.22 2999 2.26 5 .81 -7.74
2. 7730.57 3000 6.35 1 * 4.35
Neuroticism
Drop genetic innovation @ 16 years
N12 N14 N16
ε1 ε2 ε3
ζA3
1 1 1
E1
ζE1 ζE2 ζE3
βE2βE3
E2 E3
ζA1
11 1
βA2 βA3A1 A2 A3Model -2LL df 2LL df p AIC
1. 7724.22 2999 2.26 5 .81 -7.74
2. 7730.57 3000 6.35 1 * 4.35
3. 7728.02 3000 3.80 1 .05 1.80
Neuroticism
Drop genetic innovation @ 14 years
Time ζA /Var(ηA)
ζE /Var(ηE)
14 .26 .70
16 .31 .37
Neuroticism - Best fitting Simplex model
ε1
.22
.93
.49 .91
N12
A1
E1
N14
A2
E2
N16
A3
E3
ε1
.22ε1
.22
ζA2
.11ζA1
.36ζA3
.11
.76
ζE1
.39
ζE2
.22
ζE3
.15
1 1 1
1 1 1
Lie
AE Simplex model
L12 L14 L16
ε1 ε2 ε3
ζA2 ζA3
1 1 1
E1
ζE1 ζE2 ζE3
βE2βE3
E2 E3
ζA1
11 1
βA2 βA3A1 A2 A3Model -2LL df 2LL df p AIC
1. 7685.48 3000 6.75 5 .24 -3.25
Lie
Drop genetic innovation @ 16 yearsζA2
1 1 1
E1
ζE1 ζE2 ζE3
βE2βE3
E2 E3
ζA1
11 1
βA2 βA3A1 A2 A3Model -2LL df 2LL df p AIC
1. 7685.48 3000 6.75 5 .24 -3.25
2. 7694.64 3001 9.17 1 ** 7.17 L12 L14 L16
ε1 ε2 ε3
Lie
Drop genetic innovation @ 14 yearsζA3
1 1 1
E1
ζE1 ζE2 ζE3
βE2βE3
E2 E3
ζA1
11 1
βA2 βA3A1 A2 A3Model -2LL df 2LL df p AIC
1. 7685.48 3000 6.75 5 .24 -3.25
2. 7694.64 3001 9.17 1 ** 7.17
3. 7690.30 3001 4.83 1 * 2.83
L12 L14 L16
ε1 ε2 ε3
Lie - Best fitting Simplex model
ε1
.24
.84
.46 .75
L12
A1
E1
L14
A2
E2
L16
A3
E3
ε1
.24ε1
.24
ζA2
.10ζA1
.45ζA3
.15
.87
ζE1
.28
ζE2
.23
ζE3
.09
1 1 1
1 1 1
Time ζA /Var(ηA)
ζE /Var(ηE)
14 .24 .79
16 .32 .35
Discussion
Uni- and multivariate analyses
Small BUT significant genetic innovations @ 12 & 14 years
Genes which effect personality traits at all three ages +
New genetic innovations
Different environments are salient at different ages
Limitations
Normal weighted data
Removes age and sex effectsDoes not capture phenotypic variance with age
Analyses based on transformed data to remove skewness
Equivalent results !
Sex limitation
Evidence of general sex limitation for Neuroticism at 16 years
Home
Simplex model
Neuroticism final model