Table 6.
One-Sample Tests for Indexes of Stereotypicality (Test Value = 1)
| Sex | Age group | t | p | Mean difference | 95% CI | Cohen’s d |
|---|---|---|---|---|---|---|
| Fundamental frequency (F0) index of stereotypicality | ||||||
| Girls | ||||||
| 5- to 6-year-olds | t(15) = 2.69 | .017 | .06 | [.01, .11] | 0.67 | |
| 7- to 8-year-olds | t(9) = 3.12 | .012 | .16 | [.04, .27] | 0.99 | |
| 9- to 10-year-olds | t(13) = 4.31 | .001 | .19 | [.10, .29] | 1.15 | |
| Boys | ||||||
| 5- to 6-year-olds | t(11) = 0.38 | .71 | .01 | [−.05, .07] | 0.11 | |
| 7- to 8-year-olds | t(16) = 2.94 | .01 | .07 | [.02, .12] | 0.71 | |
| 9- to 10-year-olds | t(12) = 3.43 | .005 | .14 | [.05, .23] | 0.95 | |
| Formant spacing (ΔF) index of stereotypicality | ||||||
| Girls | ||||||
| 5- to 6-year-olds | t(15) = 3.95 | .001 | .02 | [.01, .04] | 0.99 | |
| 7- to 8-year-olds | t(9) = 4.12 | .003 | .02 | [.01, .03] | 1.30 | |
| 9- to 10-year-olds | t(13) = 7.09 | < .001 | .04 | [.02, .05] | 1.89 | |
| Boys | ||||||
| 5- to 6-year-olds | t(11) = 3.47 | .005 | .02 | [.01, .04] | 1.00 | |
| 7- to 8-year-olds | t(16) = 5.55 | < .001 | .03 | [.02, .04] | 1.35 | |
| 9- to 10-year-olds | t(12) = 2.10 | .047 | .02 | [.00, .04] | 0.58 | |
Note: Mean differences are between the sample means and the test value of 1 (absence of stereotyping). CI = confidence interval.