Table 1.

Means and standard deviations of observers’ and mothers’ ratings

	Time 1						Time 2
	Twin 1			Twin 2			Twin 1			Twin 2
	M	SD	Min/Max	M	SD	Min/Max	M	SD	Min/Max	M	SD	Min/Max
Observer ratings
Child neg behaviour	1.33	0.43	1.00–3.33	1.21	0.36	1.00–2.83	1.26	0.27	1.00–2.00	1.20	0.27	1.00–2.17
Child pos engage	2.17	0.50	2.17–4.33	2.33	0.69	2.33–5.33	3.39	0.66	1.83–5.00	3.85	0.73	2.33–6.00
Mother positivity	3.92	0.70	2.67–6.17	4.01	0.63	2.67–5.50	4.35	0.94	2.00–6.33	4.49	0.97	2.33–6.33
Mother negativity	1.24	0.41	1.00–3.25	1.12	0.18	1.00–1.75	1.20	0.40	1.00–3.00	1.17	0.31	1.00–2.25
Mother ratings
Externalizing	6.19	5.70	0.00–23.00	6.91	5.24	0.00–21.00	5.61	4.81	0.00–18.00	6.51	5.14	0.00–19.00
Internalizing	4.05	4.27	0.00–20.00	4.91	5.25	0.00–18.00	4.05	4.02	0.00–17.00	4.63	4.92	0.00–25.00
Mother negativity	−0.18	0.80	−1.52–2.02	−0.10	0.86	1.35–2.80	−0.04	0.73	−1.52–2.01	0.80	−0.03	−1.26–2.18
Mother positivity	0.20	0.70	−2.42–1.45	0.18	0.89	−4.56–1.49	0.13	0.82	−3.80–1.66	0.07	0.91	−4.56–1.39