Table 3.
Study 2: Descriptive Statistics and Stabilities Across Time for Infant Behavior Questionnaire (IBQ) Factors and Scales
| Descriptive Statistics | Stability | ||||
|---|---|---|---|---|---|
|
| |||||
| 6 months | 12 months | r | |||
|
| |||||
| M | SD | M | SD | ||
| Positive Affectivity | 5.01 | 0.75 | 4.78 | 0.71 | .67*** |
| Smiling and laughter | 5.42 | 0.86 | 5.36 | 0.75 | .63*** |
| Soothabilitya | 5.38 | 0.85 | 5.30 | 0.88 | .47*** |
| Duration of orienting | 4.23 | 1.17 | 3.65 | 1.15 | .56*** |
| Negative Affectivity | 3.40 | 0.61 | 3.71 | 0.59 | .59*** |
| Activity level | 4.41 | 0.87 | 4.49 | 0.89 | .56*** |
| Fear | 2.59 | 0.85 | 2.99 | 0.76 | .45*** |
| Distress to limitations | 3.19 | 0.77 | 3.65 | 0.78 | .57*** |
|
| |||||
| Average | .54*** | ||||
Note. IBQ scale scores range from 1 to 7 (1 = never, 2 = very rarely, 3 = less than half the time, 4 = about half the time, 5 = more than half the time, 6 = almost always, 7 = always).
a
Five term infants had missing data on Soothability at either one or two ages, Little’s MCAR test: χ2(32) = 40.51, p = .14, and 1 preterm infant had missing data on Soothability at 6 months, Little’s MCAR test: χ2(11) = 6.83, p = .81. As these data were all missing completely at random, the missing data points were imputed using the Expectation-Maximization algorithm (Dempster, Laird, & Rubin, 1977).
***
p ≤ .001.