Table 2.

IBQ-R Scale Means, Standard Deviations and Chronbach’s Alphas for the Entire Sample (N = 1,356), Younger (n = 731) and Older (n = 625) Infants.

IBQ-R Scale1	Entire Sample Mean (SD)	Chronbach’s Alpha	Younger Infants Mean (SD)	Younger Infants Chronbach’s Alpha	Older Infants Mean (SD)	Older Infants Chronbach’s Alpha
Activity	4.43 (0.85)	0.76	4.13 (0.83)	0.76	4.69 (0.78)	0.72
Distress to Limitations	3.70 (0.87)	0.79	3.12 (0.74)	0.75	4.06 (0.83)	0.76
Fear	2.64 (1.00)	0.88	2.21 (0.80)	0.86	3.03 (1.00)	0.87
Duration of Orienting	3.99 (1.05)	0.82	4.04 (1.04)	0.82	3.94 (1.06)	0.83
Smiling and Laughter	4.99 (1.00)	0.79	4.70 (1.05)	0.81	5.07 (0.92)	0.78
High Intensity Pleasure	5.83 (0.80)	0.84	5.57 (0.83)	0.82	6.07 (0.69)	0.84
Low Intensity Pleasure	5.14 (0.91)	0.83	5.24 (0.88)	0.83	5.03 (0.93)	0.84
Soothability	4.64 (0.93)	0.82	4.56 (0.89)	0.80	4.72 (0.97)	0.83
Falling Reactivity	4.78 (0.97)	0.81	4.81 (1.02)	0.83	4.76 (0.92)	0.79
Cuddliness	5.24 (0.94)	0.87	5.46 (0.97)	0.87	5.03 (0.87)	0.85
Perceptual Sensitivity	4.12 (1.18)	0.85	3.72 (1.16)	0.84	4.48 (1.06)	0.84
Sadness	3.46 (0.89)	0.80	3.34 (0.87)	0.82	3.56 (0.89)	0.79
Approach	5.04 (1.18)	0.87	4.50 (1.25)	0.88	5.56 (0.84)	0.83
Vocal Reactivity	4.88 (1.05)	0.84	4.44 (1.05)	0.85	5.28 (0.88)	0.82

¹Skewness. Overall sample: range −0.95 to 0.70, mean = −.08; Younger age group: range −1.09 to 0.93, mean = −0.12; Older age group: range −1.23 to 0.48, mean = −0.07.