Table 1.
The attainment of developmental milestones by explanatory variables.
| Variables | Walk Alone (in Months) | Late Walking | First Sentences (in Months) | Late Talking | Count 10 Objects (in Months) | Late Counting | Independent Toileting (in Months) | Late Toilet-Training | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mean | Sig. | % | Sig. | Mean | Sig. | % | Sig. | Mean | Sig. | % | Sig. | mean | Sig. | % | Sig. | |
| Total | 14.21 | 21.18 | 20.35 | 14.11 | 33.91 | 23.43 | 31.66 | 17.61 | ||||||||
| Maternal education | *** | *** | *** | *** | *** | *** | *** | *** | ||||||||
| No schooling | 15.87 | 35.99 | 22.23 | 22.60 | 40.22 | 39.70 | 34.50 | 24.89 | ||||||||
| Primary school | 14.29 | 22.38 | 20.69 | 14.62 | 35.98 | 29.40 | 32.85 | 21.23 | ||||||||
| Middle school | 13.65 | 16.79 | 19.54 | 10.78 | 31.87 | 17.52 | 30.27 | 13.97 | ||||||||
| High school | 13.34 | 12.31 | 19.32 | 10.51 | 29.30 | 10.02 | 29.46 | 12.09 | ||||||||
| College | 13.12 | 9.25 | 18.72 | 6.98 | 26.29 | 4.49 | 28.95 | 9.23 | ||||||||
| Gender | *** | *** | ** | *** | ** | |||||||||||
| Male | 14.25 | 21.56 | 20.75 | 15.34 | 34.54 | 24.62 | 32.00 | 18.08 | ||||||||
| Female | 14.17 | 20.74 | 19.91 | 12.72 | 33.41 | 22.30 | 31.27 | 17.07 | ||||||||
| Birth cohort | *** | *** | *** | *** | *** | *** | *** | |||||||||
| 1995–1999 | 15.25 | 30.08 | 21.79 | 20.52 | 38.44 | 36.34 | 35.56 | 27.28 | ||||||||
| 2000–2004 | 14.66 | 25.80 | 20.82 | 16.21 | 36.82 | 32.47 | 34.68 | 25.10 | ||||||||
| 2005–2009 | 13.79 | 18.40 | 19.60 | 11.80 | 31.30 | 15.58 | 29.28 | 12.15 | ||||||||
| after 2010 | 13.47 | 13.59 | 19.41 | 8.95 | 30.12 | 11.72 | 28.14 | 8.48 | ||||||||
| Minority status | *** | *** | † | *** | *** | *** | ** | |||||||||
| Han | 14.07 | 19.66 | 20.37 | 13.87 | 33.77 | 22.91 | 31.77 | 18.21 | ||||||||
| Minority | 15.31 | 32.75 | 20.20 | 15.93 | 35.91 | 28.42 | 30.81 | 12.99 | ||||||||
| Birth weight | *** | *** | *** | *** | *** | *** | *** | *** | ||||||||
| Low birth weight | 15.30 | 33.28 | 22.16 | 19.33 | 36.42 | 29.80 | 32.67 | 19.50 | ||||||||
| Normal weight | 13.90 | 18.23 | 19.97 | 12.78 | 32.67 | 19.99 | 30.99 | 16.11 | ||||||||
| Unknown | 16.47 | 41.30 | 22.61 | 22.52 | 44.23 | 50.45 | 36.96 | 29.78 | ||||||||
| Gestational age | ** | *** | ||||||||||||||
| <37 weeks | 14.83 | 29.56 | 20.48 | 12.53 | 33.41 | 20.05 | 31.21 | 16.41 | ||||||||
| ≥37 weeks | 14.19 | 20.85 | 20.35 | 14.17 | 34.03 | 23.66 | 31.67 | 17.65 | ||||||||
| Hukou before age 3 | *** | *** | *** | *** | *** | *** | *** | *** | ||||||||
| Rural | 14.42 | 23.13 | 20.60 | 15.03 | 35.29 | 26.66 | 32.05 | 18.83 | ||||||||
| Urban | 13.31 | 12.69 | 19.22 | 9.92 | 28.34 | 9.63 | 29.90 | 12.22 | ||||||||
| Mother’s age at delivery | ** | † | † | |||||||||||||
| <20 | 14.52 | 25.06 | 20.49 | 15.19 | 34.04 | 25.07 | 31.30 | 17.79 | ||||||||
| 20–24 | 14.20 | 21.06 | 20.20 | 13.88 | 33.78 | 22.63 | 31.67 | 17.87 | ||||||||
| 25–29 | 14.11 | 19.70 | 20.32 | 13.59 | 33.86 | 23.39 | 31.64 | 17.09 | ||||||||
| 30–34 | 14.32 | 23.56 | 20.61 | 14.60 | 34.74 | 25.34 | 32.16 | 19.35 | ||||||||
| 35+ | 14.44 | 22.46 | 20.76 | 16.74 | 34.51 | 24.36 | 30.62 | 14.83 | ||||||||
| N | 11,361 | 10,324 | 10,061 | 10,751 |
Notes. † p < 0.10, * p < 0.05, ** p < 0.01, *** p < 0.001; Sig. denotes significance.