1. Intro to Mx Scripts

2. Groups Data Calculation Constraint

3. Group Structure Title Reading Data Matrices Declaration Assigning Specifications/ Values Matrix Algebra Means / Covariances Options End

4. Additional Commands ! Comments #Ngroups #define

5. Matrices Declaration Begin Matrices; … End Matrices; Matrix Types: Mx manual p. 58 Matrices = Group

6. Matrix Algebra Begin Algebra; = ; … End Algebra; Matrix Operations: Mx Manual p. 61 Matrix Functions: Mx Manual p. 66

7. MZ Twins Observed Covariance Variance Twin 1 Covariance Variance Twin 2 Expected Covariance a 2+ c 2+ e 2+ d 2 a 2+ c 2+ d 2 a 2+ c 2+ e 2+ d 2

8. DZ Twins Observed Covariance Variance Twin 1 Covariance Variance Twin 2 Expected Covariance a 2+ c 2+ e 2+ d 2.5a 2+ c 2+.25d 2 a 2+ c 2+ e 2+ d 2

9. P1 A1C1E1 P2 A2C2E2D1D2 1.00 a [X]c [Y]e [Z]a [X]c [Y]e [Z] 1.00 1.00 / 0.50 [H]1.00 d [W] 1.00 d [W] 1.00 / 0.25 [Q]

10. Path Diagram to Matrices Path Coefficient aced Matrix NameXYZW Variance Component a2a2 c2c2 e2e2 d2d2 Matrix NameACED

11. MZ Twins into Mx Expected Covariance a 2+ c 2+ e 2+ d 2 a 2+ c 2+ d 2 a 2+ c 2+ e 2+ d 2 Matrix Formulation A+C+E+DA+C+D A+C+E+D

12. Path Diagram to Matrices Path Coefficient am af cm cf em ef dm df Matrix NameXLXL YMYM ZNZN WOWO Variance Component a2ma2fa2ma2f c2mc2fc2mc2f e2me2fe2me2f d2md2fd2md2f Matrix NameAGAG CFCF EJEJ DKDK

13. DZos Twins into Mx Exp. Covar. a 2 m+c 2 m+e 2 m+ d 2 m am*af’+cm*cf’+ dm*df’ af*am’+cf*cm’+ df*dm’ a 2 f+c 2 f+e 2 f+d 2 f Matrix Form. A+C+E+DH@(X*L’)+(Y*M’) +Q@(W*O’) H@(L*X’)+(M*Y’) +Q@(O*W’) G+F+J+K