Table 2.

Individual-Level and Co-Twin Control Analyses of Age-34 PID-5 Maladaptive Personality Traits and Age-34 DAS Romantic Relationship Satisfaction

				Co-Twin Control Models
		Individual-Level Models		Twin Difference Effects
		Beta (SE)	p value	Beta (SE)	p value
PID-5 (age 34)	Negative Affectivity	−0.40 (.08)	< .001	−0.37 (.16)	.021
	Anxiousness	−0.28 (.06)	< .001	−0.18 (.11)	.098
	Emotional liability	−0.23 (.07)	.002	−0.28 (.12)	.020
	Hostility	−0.28 (.08)	< .001	−0.13 (.14)	.351
	Perseveration	−0.20 (.08)	.011	−0.21 (.14)	.153
	Separation insecurity	−0.21 (.07)	.004	−0.17 (.13)	.204
	Submissiveness	−0.12 (.06)	.043	−0.27 (.09)	.005
	Detachment	−0.51 (.09)	< .001	−0.50 (.16)	.002
	Anhedonia	−0.37 (.07)	< .001	−0.27 (.12)	.028
	Depressivity	−0.57 (.10)	< .001	−0.52 (.16)	.002
	Intimacy avoidance	−0.63 (.11)	< .001	−0.69 (.15)	< .001
	Restricted affectivity	−0.12 (.07)	.083	–	–
	Suspiciousness	−0.44 (.08)	< .001	−0.47 (.14)	< .001
	Withdrawal	−0.23 (.07)	< .001	−0.17 (.11)	.131
	Antagonism	−0.25 (.11)	.022	−0.11 (.17)	.528
	Attention seeking	−0.12 (.07)	.069	–	–
	Callousness	−0.15 (.14)	.263	–	–
	Deceitfulness	−0.28 (.11)	.015	−0.08 (.18)	.671
	Grandiosity	−0.19 (.09)	.042	−0.08 (.14)	.580
	Manipulativeness	−0.08 (.07)	.227	–	–
	Disinhibition	−0.33 (.10)	< .001	−0.37 (.16)	.021
	Distractibility	−0.25 (.06)	< .001	−0.28 (.10)	.007
	Impulsivity	−0.07 (.08)	.350	–	–
	Irresponsibility	−0.50 (.11)	< .001	−0.47 (.19)	.013
	Rigid perfectionism	−0.11 (.07)	.079	–	–
	Risk taking	−0.01 (.09)	.875	–	–
	Psychoticism	−0.40 (.12)	< .001	−0.43 (.21)	.044
	Eccentricity	−0.22 (.08)	.005	−0.20 (.13)	.143
	Perceptual dysregulation	−0.41 (.14)	.004	−0.30 (.24)	.218
	Unusual beliefs	−0.30 (.10)	.004	−0.37 (.18)	.041

Notes. Results of individual-level linear mixed models (LMMs) and co-twin control models. Individual-level analyses examined associations between maladaptive personality (higher-order domains and lower-order facets), measured using the Personality Inventory for the DSM-5 (PID-5), at age 34 and romantic relationship satisfaction, measured using a brief version of the Dyadic Adjustment Scale (DAS), at age 34; individual-level analyses consider twins as individuals and were conducted in the full sample, N = 284 twins, and models included random intercepts at the twin-pair level to account for the interdependence of the twin data. Significant individual-level associations were followed up using co-twin control analyses to examine twin difference effects (co-twin control analyses were not conducted for nonsignificant individual-level associations, noted in the table with a dash); co-twin control analyses consider differences within a twin pair and were conducted in the sample of intact twin pairs, n = 210 twins (from 105 intact twin pairs), with random intercepts at the twin-pair level to account for the twin data. All models included participant age and sex as covariates.