Table 1.
Descriptive statistics for the full sample and the estimation sample.
| Variable | (1) Full sample |
(2) Estimation sample |
(3) p-Value, two-sample mean test |
||
|---|---|---|---|---|---|
| Mean | Std. dev | Mean | Std. dev | ||
| Outcome variable | |||||
| KS3 score | 100.00 | 10.00 | 103.30 | 8.49 | <0.001 |
| KS2 score | 100.00 | 10.00 | 102.40 | 8.39 | <0.001 |
| Variables of interest | |||||
| Fat mass, age 11 | 100.00 | 10.00 | 99.70 | 9.80 | 0.170 |
| Fat mass, age 9 | 100.00 | 10.00 | 99.70 | 9.69 | 0.164 |
| Contextual variables | |||||
| Percent female | 0.48 | 0.50 | 0.51 | 0.50 | 0.003 |
| Birth weight | 3395 | 560 | 3416 | 540 | 0.053 |
| Older siblings (0, 1, 2 or more) | 0.75 | 0.76 | 0.71 | 0.73 | 0.008 |
| Younger siblings (0, 1, 2 or more) | 0.46 | 0.63 | 0.53 | 0.65 | <0.001 |
| Ln (income) | 5.28 | 0.49 | 5.35 | 0.44 | <0.001 |
| Mother's education | 2.26 | 0.92 | 2.41 | 0.88 | <0.001 |
| Grandmother's education | 1.71 | 0.78 | 1.75 | 0.76 | 0.014 |
| Grandfather's education | 1.81 | 0.81 | 1.86 | 0.77 | 0.003 |
| Raised by natural father | 0.92 | 0.27 | 0.95 | 0.22 | <0.001 |
| Father's social class | 3.06 | 1.31 | 3.02 | 1.29 | 0.134 |
| Mother's age | 3.21 | 0.99 | 3.41 | 0.89 | <0.001 |
| Mother works PT, at 21 months | 0.36 | 0.48 | 0.41 | 0.49 | <0.001 |
| Mother works FT, at 21 months | 0.10 | 0.30 | 0.11 | 0.31 | 0.119 |
| Partner is employed, 21 months | 0.97 | 0.44 | 0.95 | 0.32 | 0.004 |
| IMD | 21.26 | 15.25 | 18.98 | 13.62 | <0.001 |
| Parental health and behaviour | |||||
| Mother smoked during pregnancy | 0.24 | 0.43 | 0.17 | 0.37 | <0.001 |
| Mother drank alcohol during pregnancy | 0.55 | 0.50 | 0.56 | 0.50 | 0.327 |
| Intensity of breastfeeding | 1.76 | 1.24 | 1.92 | 1.19 | <0.001 |
| Mother's ‘locus of control’ | 100.11 | 9.62 | 98.45 | 9.39 | <0.001 |
| Mother's CCEI | 13.65 | 7.74 | 12.67 | 7.14 | <0.001 |
| Mother's EPDS | 6.95 | 4.83 | 6.24 | 4.50 | <0.001 |
| Mother's teaching score | 7.01 | 1.09 | 7.04 | 0.90 | 0.121 |
| Interest in child's development | 0.69 | 0.21 | 0.69 | 0.20 | 1.000 |
| Parent's activity score | 27.73 | 4.95 | 27.90 | 4.53 | 0.087 |
| Instrumental variables | |||||
| Mother's BMI | 100.00 | 10.00 | 100.16 | 9.63 | 0.425 |
| Child weight categories | 3.00 | 0.77 | 2.99 | 0.76 | 0.552 |
| FTO (categorical, with values 0, 1 and 2) | 0.79 | 0.69 | 0.79 | 0.69 | 0.788 |
| MC4R (binary, values 0, 1) | 0.43 | 0.49 | 0.42 | 0.49 | 0.340 |
| Number of observations | 12.620 | 3001 | |||
Note: The descriptive statistics of the full sample are based on a maximum of 12.620 observations if the variable reported in the column has no missing values on any observations.