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Table 3 Twin model fit statistics

From: Etiological influences on the stability of autistic traits from childhood to early adulthood: evidence from a twin study

Full model
 Model -2LL Parameters df AIC BIC Δχ 2 Δdf p
 Saturated 25,044.31 70 9494 6056.31 −49,743.70
 ADEs 25,155.82 28 9536 6083.82 −49,963.04 111.51 42 <.001
Nested models
 Model -2LL Parameters df AIC BIC Δχ 2 Δdf p
 ADE scalar 25,160.31 25 9539 6082.31 −49,982.19 4.84 3 .21
 ADE hom. 25,220.50 15 9549 6122.50 −50,000.77 64.68 13 <.001
 AE scalar 25,165.81 20 9544 6077.81 −50,016.07 9.99 8 .27
 AE scalar 25,208.87 14 9550 6108.87 −50,020.27 53.05 14 <.001
 E scalar 26,053.90 9 9555 6943.90 −49,214.63 898.08 19 <.001
  1. Statistics for the ADEs model are in comparison with the saturated model. Statistics for all other models are in comparison to the ADEs model. Saturated model: model of the observed data, allowing means and variances to differ across twin order and zygosity. All other models constrain means and variances to be equal across twin order and zygosity
  2. -2LL fit statistic, which is -2*log-likelihood of the data, df degrees of freedom, AIC Akaike’s Information Criteria, BIC Bayesian Information Criteria, Δχ 2 change in -2LL between two models, distributed, χ2, Δdf change in degrees of freedom between two models, A additive genetic influence, D non-additive genetic influence, E nonshared environmental influence, s sibling interaction effects, hom. homogeneity model, which collapsed all estimates across sex