Table 2.

Descriptive Statistics for Infant Cognitive Behaviors and Adoptive-Birth Group Differences

	Adoptive			Birth
Behaviors	M	SD	N	M	SD	N	F	df	p≤	η2p
Alert expression: Mean z score	3.88	1.04	37	4.50	1.16	37	8.92	67	.004	.12
Frequency: Rate per hour	102.02	43.16	37	135.37	34.54	37
Duration: Proportion of hour	.75	.11	37	.73	.09	37
Non-distress vocalization: Mean z score	3.89	1.92	37	4.19	1.73	37	1.13	67	ns	.02
Frequency: Rate per hour	140.41	74.74	37	150.13	73.54	37
Duration: Proportion of hour	.08	.06	37	.09	.05	37
Look at object: Mean z score	4.36	1.55	37	3.90	1.51	37	1.45	67	ns	.02
Frequency: Rate per hour	153.91	43.79	37	139.01	42.90	37
Duration: Proportion of hour	.35	.12	37	.33	.13	37
Touch object: Mean z score	3.20	1.50	37	3.99	1.60	37	3.64	67	ns	.05
Frequency: Rate per hour	60.80	32.48	37	88.74	42.33	37
Duration: Proportion of hour	.25	.13	37	.26	.13	37
Mouth object: Mean z score	3.47	1.48	37	4.46	1.90	37	4.41	67	.04	.06
Frequency: Rate per hour	30.46	19.70	37	48.75	30.09	37
Duration: Proportion of hour	.10	.07	37	.12	.08	37
Extent of exploration: Mean z score	2.64	.82	37	2.93	.99	37	2.91	67	ns	.04
Variety	7.86	3.58	37	8.43	4.26	37
Density	1.38	.60	37	1.67	1.00	37
Consistency	6.65	1.99	37	7.43	2.12	37
Efficiency of Exploration: Mean z score	3.39	.92	37	3.47	.75	37	.25	67	ns	.004
Percentile: Variety	.78	.18	37	.78	.16	37
Percentile: Density	.64	.18	37	.63	.17	37
Percentile: Consistency	.88	.14	37	.92	.11	37
Balance: Mean z score	2.83	1.19	37	2.51	.74	35	.60	67	ns	.01
Movement: Mean z score	1.70	.85	35	2.06	1.11	36	3.43	67	ns	.05