Mplus VERSION 2.12
MUTHEN & MUTHEN
04/28/2003 12:21 PM
INPUT INSTRUCTIONS
! INPUT FILE FOR EXAMPLE 1 from BG MS # 020404 by C Prescott
TITLE: 2-group Univariate Twin Model for a Continuous Variable
DATA: FILE = example1.dat;
VARIABLE: NAMES = famno zyg y1 y2;
USEVARIABLEs = y1 y2;
GROUP = zyg(1=mz 2=dz);
ANALYSIS: TYPE = MEANSTRUCTURE;
MODEL: ! set up values for a
[y1*100] (1); [y2*100] (1); ! means
y1@0; y2@0; ! fix residual variances to zero
A1 BY y1*5 (11); A2 BY y2*5 (11); ! additive genetic loadings
C1 BY y1*5 (12); C2 BY y2*5 (12); ! common envt loadings
E1 BY y1*8 (13); E2 BY y2*8 (13); ! specific envt loadings
[A1@0 A2@0 C1@0 C2@0 E1@0 E2@0]; ! fix latent variable
A1@1 A2@1 C1@1 C2@1 E1@1 E2@1; ! fix latent varia
A1 WITH A2@1; A1 WITH C1-E2@0; A2 WITH C1-E2@0; ! latent variable corrs
C1 WITH C2@1; C1 WITH E1-E2@0; C2 WITH E1-E2@0;
E1 WITH E2@0;
MODEL dz: ! parameters which differ from 1st g
A1 WITH A2@0.5;
OUTPUT: SAMP RES STAND;
INPUT READING TERMINATED NORMALLY
2-group Univariate Twin Model for a Continuous Variable
SUMMARY OF ANALYSIS
Number of groups 2
Number of observations
Group MZ 1000
Group DZ 1000
Number of y-variables 2
Number of x-variables 0
Number of continuous latent variables 6
Observed variables in the analysis
Y1 Y2
Grouping variable ZYG
Continuous latent variables in the analysis
A1 A2 C1 C2 E1 E2
Estimator ML
Maximum number of iterations 1000
Convergence criterion 0.500D-04
Maximum number of steepest descent iterations 20
Input data file(s)
example1.dat
Input data format FREE
SAMPLE STATISTICS
SAMPLE STATISTICS FOR MZ
Means
Y1 Y2
________ ________
1 100.385 100.235
Covariances
Y1 Y2
________ ________
Y1 98.756
Y2 57.743 96.296
Correlations
Y1 Y2
________ ________
Y1 1.000
Y2 0.592 1.000
SAMPLE STATISTICS FOR DZ
Means
Y1 Y2
________ ________
1 100.116 100.076
Covariances
Y1 Y2
________ ________
Y1 90.747
Y2 37.176 101.818
Correlations
Y1 Y2
________ ________
Y1 1.000
Y2 0.387 1.000
THE MODEL ESTIMATION TERMINATED NORMALLY
TESTS OF MODEL FIT
Chi-Square Test of Model Fit
Value 4.818
Degrees of Freedom 6
P-Value 0.5673
Chi-Square Test of Model Fit for the Baseline Model
Value 593.758
Degrees of Freedom 2
P-Value 0.0000
CFI/TLI
CFI 1.000
TLI 1.001
Loglikelihood
H0 Value -14524.953
H1 Value -14522.545
Information Criteria
Number of Free Parameters 4
Akaike (AIC) 29057.907
Bayesian (BIC) 29080.310
Sample-Size Adjusted BIC 29067.602
(n* = (n + 2) / 24)
RMSEA (Root Mean Square Error Of Approximation)
Estimate 0.000
90 Percent C.I. 0.000 0.036
SRMR (Standardized Root Mean Square Residual)
Value 0.028
MODEL RESULTS
Estimates S.E. Est./S.E. Std StdYX
Group MZ
A1 BY
Y1 6.255 0.481 12.999 6.255 0.636
A2 BY
Y2 6.255 0.481 12.999 6.255 0.636
C1 BY
Y1 4.239 0.621 6.822 4.239 0.431
C2 BY
Y2 4.239 0.621 6.822 4.239 0.431
E1 BY
Y1 6.298 0.138 45.493 6.298 0.640
E2 BY
Y2 6.298 0.138 45.493 6.298 0.640
A1 WITH
A2 1.000 0.000 0.000 1.000 1.000
C1 0.000 0.000 0.000 0.000 0.000
C2 0.000 0.000 0.000 0.000 0.000
E1 0.000 0.000 0.000 0.000 0.000
E2 0.000 0.000 0.000 0.000 0.000
A2 WITH
C1 0.000 0.000 0.000 0.000 0.000
C2 0.000 0.000 0.000 0.000 0.000
E1 0.000 0.000 0.000 0.000 0.000
E2 0.000 0.000 0.000 0.000 0.000
C1 WITH
C2 1.000 0.000 0.000 1.000 1.000
E1 0.000 0.000 0.000 0.000 0.000
E2 0.000 0.000 0.000 0.000 0.000
C2 WITH
E1 0.000 0.000 0.000 0.000 0.000
E2 0.000 0.000 0.000 0.000 0.000
E1 WITH
E2 0.000 0.000 0.000 0.000 0.000
Means
A1 0.000 0.000 0.000 0.000 0.000
A2 0.000 0.000 0.000 0.000 0.000
C1 0.000 0.000 0.000 0.000 0.000
C2 0.000 0.000 0.000 0.000 0.000
E1 0.000 0.000 0.000 0.000 0.000
E2 0.000 0.000 0.000 0.000 0.000
Intercepts
Y1 100.196 0.189 529.142 100.196 10.185
Y2 100.196 0.189 529.142 100.196 10.185
Variances
A1 1.000 0.000 0.000 1.000 1.000
A2 1.000 0.000 0.000 1.000 1.000
C1 1.000 0.000 0.000 1.000 1.000
C2 1.000 0.000 0.000 1.000 1.000
E1 1.000 0.000 0.000 1.000 1.000
E2 1.000 0.000 0.000 1.000 1.000
Residual Variances
Y1 0.000 0.000 0.000 0.000 0.000
Y2 0.000 0.000 0.000 0.000 0.000
Group DZ
A1 BY
Y1 6.255 0.481 12.999 6.255 0.636
A2 BY
Y2 6.255 0.481 12.999 6.255 0.636
C1 BY
Y1 4.239 0.621 6.822 4.239 0.431
C2 BY
Y2 4.239 0.621 6.822 4.239 0.431
E1 BY
Y1 6.298 0.138 45.493 6.298 0.640
E2 BY
Y2 6.298 0.138 45.493 6.298 0.640
A1 WITH
A2 0.500 0.000 0.000 0.500 0.500
C1 0.000 0.000 0.000 0.000 0.000
C2 0.000 0.000 0.000 0.000 0.000
E1 0.000 0.000 0.000 0.000 0.000
E2 0.000 0.000 0.000 0.000 0.000
A2 WITH
C1 0.000 0.000 0.000 0.000 0.000
C2 0.000 0.000 0.000 0.000 0.000
E1 0.000 0.000 0.000 0.000 0.000
E2 0.000 0.000 0.000 0.000 0.000
C1 WITH
C2 1.000 0.000 0.000 1.000 1.000
E1 0.000 0.000 0.000 0.000 0.000
E2 0.000 0.000 0.000 0.000 0.000
C2 WITH
E1 0.000 0.000 0.000 0.000 0.000
E2 0.000 0.000 0.000 0.000 0.000
E1 WITH
E2 0.000 0.000 0.000 0.000 0.000
Means
A1 0.000 0.000 0.000 0.000 0.000
A2 0.000 0.000 0.000 0.000 0.000
C1 0.000 0.000 0.000 0.000 0.000
C2 0.000 0.000 0.000 0.000 0.000
E1 0.000 0.000 0.000 0.000 0.000
E2 0.000 0.000 0.000 0.000 0.000
Intercepts
Y1 100.196 0.189 529.142 100.196 10.185
Y2 100.196 0.189 529.142 100.196 10.185
Variances
A1 1.000 0.000 0.000 1.000 1.000
A2 1.000 0.000 0.000 1.000 1.000
C1 1.000 0.000 0.000 1.000 1.000
C2 1.000 0.000 0.000 1.000 1.000
E1 1.000 0.000 0.000 1.000 1.000
E2 1.000 0.000 0.000 1.000 1.000
Residual Variances
Y1 0.000 0.000 0.000 0.000 0.000
Y2 0.000 0.000 0.000 0.000 0.000
R-SQUARE
Group MZ
Observed
Variable R-Square
Y1 1.000
Y2 1.000
Group DZ
Observed
Variable R-Square
Y1 1.000
Y2 1.000
RESIDUAL OUTPUT
ESTIMATED MODEL AND RESIDUALS (OBSERVED - ESTIMATED) FOR MZ
Model Estimated Means/Intercepts/Thresholds
Y1 Y2
________ ________
1 100.196 100.196
Residuals for Means/Intercepts/Thresholds
Y1 Y2
________ ________
1 0.189 0.039
Model Estimated Covariances/Correlations/Residual Correlations
Y1 Y2
________ ________
Y1 96.769
Y2 57.098 96.769
Residuals for Covariances/Correlations/Residual Correlations
Y1 Y2
________ ________
Y1 1.887
Y2 0.587 -0.570
ESTIMATED MODEL AND RESIDUALS (OBSERVED - ESTIMATED) FOR DZ
Model Estimated Means/Intercepts/Thresholds
Y1 Y2
________ ________
1 100.196 100.196
Residuals for Means/Intercepts/Thresholds
Y1 Y2
________ ________
1 -0.080 -0.120
Model Estimated Covariances/Correlations/Residual Correlations
Y1 Y2
________ ________
Y1 96.769
Y2 37.534 96.769
Residuals for Covariances/Correlations/Residual Correlations
Y1 Y2
________ ________
Y1 -6.113
Y2 -0.394 4.947
Beginning Time: 12:21:03
Ending Time: 12:21:03
Elapsed Time: 00:00:00
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