Presentation on theme: "Patterns of Actor and Partner Effects"— Presentation transcript:
1 Patterns of Actor and Partner Effects David A. Kenny
2 You need to know the Actor Partner Interdependence Model! APIM
3 APIM Patterns: Couple Model Equal actor and partner effects: a = pe.g., my depressive symptoms has the same effect on my quality of life as does my partner’s depressive symptoms on my quality of lifeAverage or sum as the predictorAlthough measured individually, the predictor variable is a “dyadic” variable, not an individual one
4 APIM Patterns: Contrast ModelActor plus partner effects equals zero: a – p = 0Klumb et al. (2006): time spent doing household labor on stress levelsThe more household labor I do, the more stressed I feel.The more household labor my partner does, the less stress I feel.Difference score (actor X minus partner X) as the predictor
5 APIM Patterns: Actor or Partner Only Actor OnlyActor present but no partner effectFix the partner effect to zero.Partner OnlyPartner present but no partner effectFix the actor effect to zero.Relatively rare.
6 Testing Patterns Multilevel Modeling Structural Equation Modeling Sum and difference approachStructural Equation ModelingSetting coefficients equalUse of phantom variablesGeneral approach to patterns: k
7 Sum and Difference Approach Remove the actor and partner variables from the model.Add to the model the Sum and the Difference score as predictors.If Sum is present, but not the Difference, you have a couple model.If Sum is not present, but the Difference is, you have a contrast model.
8 Acitelli Example Distinguishable Husbands Sum: 0.392, p < .001 Difference: 0.131, p = .088WivesSum: 0.373, p < .001Difference: 0.001, p = .986IndistinguishableSum: 0.344, p < .001Difference: 0.056, p = .052
9 Testing the Couple Model Using SEM Actor effect equal to the partner effect.Can be done by setting paths equal.Distinguishable dyadsa1 = p12 and a2 = p21Indistinguishable dyadsa = p
10 Acitelli Example Distinguishable Husbands: 0.346 Wives: 0.347 Test: c2(2) = 4.491, p = .106IndistinguishableEffect: 0.344Test: c2(1) = 3.803, p = .051
11 Testing the Contrast Model Using SEM Actor effect equal to the partner effect times minus 1.Can be done by using a phantom variable.Phantom variableNo conceptual meaningForces a constraintLatent variableNo disturbance
12 Contrast Constraint Forced by Phantom Variables (P1 and P2) X1a1Y11E1-1a2P1a1P2-1X2Y21E2a2Now the indirect effect from X2 to Y1, p12 equals (-1)a1
14 ConclusionUsing patterns can link the APIM to theory and simplify the model. The k parameter is a general way to measure and test patterns Readings pp , in Dyadic Data Analysis by Kenny, Kashy, and Cook Kenny & Cook, (1999), Personal Relationships, 6, pp