! Sibling Interaction Model ! CBC data in US twins The following MX script lines were read for group 1 G1: MODEL PARAMETERS CALC NGROUPS=3 BEGIN MATRICES; X LOWER 1 1 FREE ! ADDITIVE GENETIC PATH Y LOWER 1 1 FREE ! SHARED ENVIRONMENT PATH Z LOWER 1 1 FREE ! NON-SHARED ENVIRONMENTAL PATH B SYMM 2 2 ! SIBLING INTERACTION PARAMETER I IDEN 2 2 H FULL 1 1 END MATRICES; SPECIFY B 0 4 0 MATRIX H .5 BEGIN ALGEBRA; A= X*X' ; C= Y*Y' ; E= Z*Z' ; P= (I-B)~; END ALGEBRA; OPTIONS NO_OUTPUT END The following MX script lines were read for group 2 G2: MALE MZ TWINS IN LARGER FAMILIES DATA NINPUT_VARS=2 NOBSERVATIONS=171 LABELS EXTER1 EXTER2 CMATRIX SYMMETRIC FILE=USCBCMZ.COV MATRICES= GROUP 1 COVARIANCES (P* (A+C+E | A+C _ A+C | A+C+E) * P') / OPTIONS RSIDUAL END The following MX script lines were read for group 3 G3: MALE DZ TWINS IN LARGER FAMILIES DATA NINPUT_VARS=2 NOBSERVATIONS=194 LABELS EXTER1 EXTER2 CMATRIX SYMMETRIC FILE=USCBCDZ.COV MATRICES= GROUP 1 COVARIANCES (P* (A+C+E | H@A+C _ H@A+C | A+C+E) * P') / START .3 ALL START .0 B 1 2 1 OPTIONS NDECIMALS=4 OPTIONS RSIDUAL END PARAMETER SPECIFICATIONS GROUP NUMBER: 2 G2: Male MZ twins in larger families MATRIX A This is a computed FULL matrix of order 1 by 1 It has no free parameters specified MATRIX B This is a SYMMETRIC matrix of order 2 by 2 1 2 1 0 2 4 0 MATRIX C This is a computed FULL matrix of order 1 by 1 It has no free parameters specified MATRIX E This is a computed FULL matrix of order 1 by 1 It has no free parameters specified MATRIX H This is a FULL matrix of order 1 by 1 It has no free parameters specified MATRIX I This is an IDENTITY matrix of order 2 by 2 MATRIX P This is a computed FULL matrix of order 2 by 2 It has no free parameters specified MATRIX X This is a LOWER TRIANGULAR matrix of order 1 by 1 1 1 1 MATRIX Y This is a LOWER TRIANGULAR matrix of order 1 by 1 1 1 2 MATRIX Z This is a LOWER TRIANGULAR matrix of order 1 by 1 1 1 3 GROUP NUMBER: 3 G3: Male DZ twins in larger families MATRIX A This is a computed FULL matrix of order 1 by 1 It has no free parameters specified MATRIX B This is a SYMMETRIC matrix of order 2 by 2 1 2 1 0 2 4 0 MATRIX C This is a computed FULL matrix of order 1 by 1 It has no free parameters specified MATRIX E This is a computed FULL matrix of order 1 by 1 It has no free parameters specified MATRIX H This is a FULL matrix of order 1 by 1 It has no free parameters specified MATRIX I This is an IDENTITY matrix of order 2 by 2 MATRIX P This is a computed FULL matrix of order 2 by 2 It has no free parameters specified MATRIX X This is a LOWER TRIANGULAR matrix of order 1 by 1 1 1 1 MATRIX Y This is a LOWER TRIANGULAR matrix of order 1 by 1 1 1 2 MATRIX Z This is a LOWER TRIANGULAR matrix of order 1 by 1 1 1 3 MX PARAMETER ESTIMATES GROUP NUMBER: 2 G2: Male MZ twins in larger families MATRIX A This is a computed FULL matrix of order 1 by 1 [=X*X'] 1 1 0.3739 MATRIX B This is a SYMMETRIC matrix of order 2 by 2 1 2 1 0.0000 2 0.2302 0.0000 MATRIX C This is a computed FULL matrix of order 1 by 1 [=Y*Y'] 1 1 0.0000 MATRIX E This is a computed FULL matrix of order 1 by 1 [=Z*Z'] 1 1 0.1754 MATRIX H This is a FULL matrix of order 1 by 1 1 1 0.5000 MATRIX I This is an IDENTITY matrix of order 2 by 2 MATRIX P This is a computed FULL matrix of order 2 by 2 [=(I-B)~] 1 2 1 1.0559 0.2431 2 0.2431 1.0559 MATRIX X This is a LOWER TRIANGULAR matrix of order 1 by 1 1 1 0.6115 MATRIX Y This is a LOWER TRIANGULAR matrix of order 1 by 1 1 1 0.0000 MATRIX Z This is a LOWER TRIANGULAR matrix of order 1 by 1 1 1 0.4188 OBSERVED COVARIANCE MATRIX EXTER1 EXTER2 EXTER1 0.9230 EXTER2 0.7980 0.9070 EXPECTED COVARIANCE MATRIX EXTER1 EXTER2 EXTER1 0.8369 EXTER2 0.7210 0.8369 RESIDUAL MATRIX EXTER1 EXTER2 EXTER1 0.0861 EXTER2 0.0770 0.0701 Function value of this group: 0.8519 Where the fit function is Maximum Likelihood GROUP NUMBER: 3 G3: Male DZ twins in larger families MATRIX A This is a computed FULL matrix of order 1 by 1 [=X*X'] 1 1 0.3739 MATRIX B This is a SYMMETRIC matrix of order 2 by 2 1 2 1 0.0000 2 0.2302 0.0000 MATRIX C This is a computed FULL matrix of order 1 by 1 [=Y*Y'] 1 1 0.0000 MATRIX E This is a computed FULL matrix of order 1 by 1 [=Z*Z'] 1 1 0.1754 MATRIX H This is a FULL matrix of order 1 by 1 1 1 0.5000 MATRIX I This is an IDENTITY matrix of order 2 by 2 MATRIX P This is a computed FULL matrix of order 2 by 2 [=(I-B)~] 1 2 1 1.0559 0.2431 2 0.2431 1.0559 MATRIX X This is a LOWER TRIANGULAR matrix of order 1 by 1 1 1 0.6115 MATRIX Y This is a LOWER TRIANGULAR matrix of order 1 by 1 1 1 0.0000 MATRIX Z This is a LOWER TRIANGULAR matrix of order 1 by 1 1 1 0.4188 OBSERVED COVARIANCE MATRIX EXTER1 EXTER2 EXTER1 0.6710 EXTER2 0.4480 0.7000 EXPECTED COVARIANCE MATRIX EXTER1 EXTER2 EXTER1 0.7410 EXTER2 0.5015 0.7410 RESIDUAL MATRIX EXTER1 EXTER2 EXTER1 -0.0700 EXTER2 -0.0535 -0.0410 Function value of this group: 0.9457 Where the fit function is Maximum Likelihood Your model has 4 estimated parameters and 6 Observed statistics Chi-squared fit of model >>>>>>> 1.798 Degrees of freedom >>>>>>>>>>>>> 2 Probability >>>>>>>>>>>>>>>>>>>> 0.407 Akaike's Information Criterion > -2.202 RMSEA >>>>>>>>>>>>>>>>>>>>>>>>>> 0.000 This problem used 0.5% of my workspace Task Time elapsed (DD:HH:MM:SS) Reading script & data 0: 0: 0: 0.06 Execution 0: 0: 0: 0.11 TOTAL 0: 0: 0: 0.17 Total number of warnings issued: 0 ______________________________________________________________________________