Table 1. Descriptive Statistics and Correlations among Study Variables (N = 301).
| Source | Time | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Effortful control | ||||||||||||||||
| 1. Effortful control | Parent | Fall K | --- | |||||||||||||
| 2. Effortful control | Teacher | Fall K | .46*** | --- | ||||||||||||
| 3. Effortful control | Observer | Fall K | .34*** | .56*** | --- | |||||||||||
| 4. Continuous performance | CPT | Fall K | .25*** | .30*** | .27*** | --- | ||||||||||
| Teacher-student relationship | ||||||||||||||||
| 5. Teacher-student closeness | Teacher | Spring K | .12† | .27*** | .08 | .01 | --- | |||||||||
| 6. Teacher-student conflict | Teacher | Spring K | -.30*** | -.54*** | -.53*** | -.19*** | -.36*** | --- | ||||||||
| Academic achievement | ||||||||||||||||
| 7. Applied problems | WJ | Spring K | .21*** | .25*** | .20* | .27*** | .08 | -.14* | --- | |||||||
| 8. Applied problems | WJ | Spring 1st | .13† | .24*** | .13* | .12† | .15* | -.14* | .69*** | --- | ||||||
| 9. Passage comprehension | WJ | Spring K | .15* | .27*** | .22*** | .19*** | .06 | -.14* | .53*** | .52*** | --- | |||||
| 10. Passage comprehension | WJ | Spring 1st | .22** | .31*** | .17** | .14* | .13* | -.17** | .54*** | .58*** | .62*** | --- | ||||
| Covariates | ||||||||||||||||
| 11. Age | Parent | Fall K | .06 | .12* | .08 | -.07 | .06 | .04 | .03 | -.02 | .02 | -.09 | --- | |||
| 12. Male | Parent | Fall K | -.13* | -.16** | -.08 | -.22*** | -.10† | .03 | .16** | .24*** | .03 | .01 | .12* | --- | ||
| 13. Hispanic | Parent | Fall K | -.06 | -.02 | -.06 | .03 | -.04 | -.01 | -.27*** | -.29*** | -.19*** | -.31*** | .11† | -.08 | --- | |
| 14. Socioeconomic status | Parent | Fall K | .11 | .12* | .12* | .18** | -.01 | -.05 | .46*** | .38*** | .39*** | .41*** | -.10† | .11† | -.38*** | --- |
| M | 4.83 | 4.80 | 5.32 | 2.94 | 4.38 | 1.55 | 442.84 | 461.72 | 428.53 | 464.67 | 5.48 | .49 | .57 | -0.04 | ||
| SD | .77 | 1.21 | .96 | .90 | .63 | .86 | 15.83 | 16.31 | 20.96 | 18.47 | .35 | .50 | .50 | 0.90 | ||
| Possible min/max | 1 / 7 | 1 / 7 | 1 / 7 | # | 1 / 5 | 1 / 5 | 500 a | 500 a | 500 a | 500 a | ## | 0 / 1 | 0 / 1 | # | ||
| Actual min/max | 2.7 / 6.7 | 1.4 / 7 | 1.4 / 6.9 | -.16 / 4.5 | 1.5 / 5 | 1 / 5 | 388 / 504 | 403 / 528 | 368 / 503 | 391 / 525 | 4.3 / 6.8 | 0 / 1 | 0 / 1 | -1.8 / 1.2 | ||
Note. Male (1 = boy; 0 = girl); Hispanic (1 = Hispanic, 0 = non-Hispanic); CPT = Continuous performance task; WJ = Woodcock-Johnson assessment; Fall K = fall, kindergarten; Spring K = spring, kindergarten; Spring 1st = spring, first grade; Min = minimum; Max = maximum. # There is no exact possible range for the difference or average of standardized variables. ## Age admission policies vary by schools, including family requests to enroll a child earlier or later than typical; a range of possible ages is not listed.
The scale for each test is centered to a W score of 500, which is the average performance of 10-year-olds, but the range of possible scores is not listed in the Woodcock-Johnson III Tests of Achievement Technical Manual. †p < .10.
p < .05.
p < .01.
p < .001.