Classification | Average | Standard deviation | Minimum value | Maximum value | Number | t/F |
---|---|---|---|---|---|---|
The whole | 19.93 | 16.90 | 1.00 | 120.00 | 1325 | |
Birth order | ||||||
First-born | 21.12 | 18.00 | 1.00 | 120.00 | 638 | 8.63*** |
Second-born | 19.93 | 16.13 | 1.00 | 100.00 | 540 | |
Third or more | 14.73 | 13.50 | 1.00 | 100.00 | 147 | |
Employment of mother | ||||||
Employed | 22.23 | 16.48 | 1.00 | 100.00 | 604 | 4.63*** |
Not-employed | 17.94 | 17.00 | 1.00 | 120.00 | 712 | |
Educational level of mother | ||||||
High school or less | 13.74 | 13.26 | 1.00 | 100.00 | 418 | 75.24*** |
Community college graduates | 17.64 | 15.03 | 1.00 | 110.00 | 355 | |
College graduates | 26.08 | 18.36 | 1.00 | 120.00 | 547 | |
Household income | ||||||
Less than \3,000,000 | 12.46 | 13.53 | 1.00 | 120.00 | 439 | 75.35*** |
\3,010,000 to \4,000,000 | 18.31 | 15.05 | 1.00 | 100.00 | 292 | |
\4,010,000 to \5,300,000 | 22.23 | 17.26 | 1.00 | 100.00 | 236 | |
over \5,310,000 | 28.89 | 17.31 | 1.00 | 110.00 | 358 | |
Regional scale | ||||||
Big cities | 20.09 | 17.23 | 1.00 | 120.00 | 525 | 15.51*** |
Small and medium cities | 22.25 | 17.51 | 1.00 | 110.00 | 518 | |
Small towns | 15.36 | 14.06 | 1.00 | 70.00 | 282 |