. Author manuscript; available in PMC: 2017 Feb 1.

Published in final edited form as: Twin Res Hum Genet. 2016 Aug;19(4):297–305. doi: 10.1017/thg.2016.52

Table 3.

Multivariate model fitting results for the (i) non-causal correlated liability, (ii) reciprocal causation (PM↔DI), (iii) uni-directional Parental Monitoring causes Drug Initiation (PM→DI), and (iv) uni-directional Drug Initiation causes Parental Monitoring (DI→PM) models.

	−2LL	df	Δ −2LL	Δdf	p	AIC
Correlated Liability	14548.68	12950	-	-	-	−11351.32
Reciprocal Causation	14552.96	12951	4.28	1	0.04	−11349.04
PM→DI	14596.70	12952	48.03	2	^***	−11307.30
DI→PM	14567.76	12952	19.08	2	^***	−11336.24

Note: All PM & DI thresholds are adjusted for the linear effects of age at interview. −2LL = log-likelihood, Δ−2LL=change in log-likelihood which is asymptotically distributed as a chi-square, AIC=Akaike Information Criteria,

^***

= p < 0.001