Table 2. Characteristics of participants.
| Total number | Spanking | |||||||
| Never | Sometimes | Always | P-value | |||||
| n | n | Proportion | n | Proportion | n | Proportion | ||
| Total | 70,450 | 20,581 | 29.2 | 44,271 | 62.8 | 5,598 | 7.9 | <0.01 |
| Respondent of the survey | ||||||||
| Mother | 62,349 | 17,582 | 28.2 | 39,672 | 63.6 | 5,095 | 8.2 | <0.01 |
| Father | 4,140 | 1,587 | 38.3 | 2,280 | 55.1 | 273 | 6.6 | |
| Both | 3,290 | 1,198 | 36.4 | 1,910 | 58.1 | 182 | 5.5 | |
| Other family members | 671 | 214 | 31.9 | 409 | 61.0 | 48 | 7.2 | |
| Caregiver of the child | ||||||||
| Mother | 31,894 | 8,933 | 28.0 | 20,218 | 63.4 | 2,743 | 8.6 | <0.01 |
| Father | 174 | 63 | 36.2 | 102 | 58.6 | 9 | 5.2 | |
| Both | 32,972 | 9,952 | 30.2 | 20,655 | 62.6 | 2,365 | 7.2 | |
| Others | 5,410 | 1,633 | 30.2 | 3,296 | 60.9 | 481 | 8.9 | |
| Cohort generation | ||||||||
| First | 41,193 | 9,391 | 22.8 | 27,727 | 67.3 | 4,075 | 9.9 | <0.01 |
| Second | 29,257 | 11,190 | 38.2 | 16,544 | 56.5 | 1,523 | 5.2 | |
| Gender of the child | ||||||||
| Boy | 36,465 | 9,109 | 25.0 | 23,907 | 65.6 | 3,449 | 9.5 | <0.01 |
| Girl | 33,985 | 11,472 | 33.8 | 20,364 | 59.9 | 2,149 | 6.3 | |
| Presence of siblings of the child | ||||||||
| Yes | 53,534 | 14,478 | 27.0 | 34,564 | 64.6 | 4,492 | 8.4 | <0.01 |
| Living in a two-parent household | ||||||||
| No | 3,300 | 908 | 27.5 | 2,056 | 62.3 | 336 | 10.2 | <0.01 |
| Living in a three-generation household | ||||||||
| Yes | 12,756 | 3,915 | 30.7 | 7,756 | 60.8 | 1,085 | 8.5 | <0.01 |
| Mother’s age, years | ||||||||
| <25 | 1,377 | 320 | 23.2 | 858 | 62.3 | 199 | 14.5 | <0.01 |
| 25–29 | 10,545 | 2,481 | 23.5 | 6,824 | 64.7 | 1,240 | 11.8 | |
| 30–34 | 27,867 | 7,759 | 27.8 | 17,827 | 64.0 | 2,281 | 8.2 | |
| 35–39 | 22,649 | 7,088 | 31.3 | 14,094 | 62.2 | 1,467 | 6.5 | |
| 40–44 | 7,336 | 2,675 | 36.5 | 4,279 | 58.3 | 382 | 5.2 | |
| ≥45 | 676 | 258 | 38.2 | 389 | 57.5 | 29 | 4.3 | |
| Father’s age, years | ||||||||
| <25 | 810 | 205 | 25.3 | 502 | 62.0 | 103 | 12.7 | <0.01 |
| 25–29 | 7,219 | 1,674 | 23.2 | 4,689 | 65.0 | 856 | 11.9 | |
| 30–34 | 22,023 | 5,920 | 26.9 | 14,178 | 64.4 | 1,925 | 8.7 | |
| 35–39 | 23,812 | 7,272 | 30.5 | 14,851 | 62.4 | 1,689 | 7.1 | |
| 40–44 | 12,163 | 4,034 | 33.2 | 7,386 | 60.7 | 743 | 6.1 | |
| ≥45 | 4,423 | 1,476 | 33.4 | 2,665 | 60.3 | 282 | 6.4 | |
| Mother’s education | ||||||||
| Junior high school | 2,268 | 540 | 23.8 | 1,438 | 63.4 | 290 | 12.8 | <0.01 |
| High school | 22,952 | 5,464 | 23.8 | 15,133 | 65.9 | 2,355 | 10.3 | |
| Vocational | 13,388 | 3,591 | 26.8 | 8,683 | 64.9 | 1,114 | 8.3 | |
| Junior college | 16,082 | 4,874 | 30.3 | 10,142 | 63.1 | 1,066 | 6.6 | |
| University and higher | 13,539 | 5,435 | 40.1 | 7,510 | 55.5 | 594 | 4.4 | |
| Others | 120 | 50 | 41.7 | 64 | 53.3 | 6 | 5.0 | |
| Missing | 2,101 | 627 | 29.8 | 1,301 | 61.9 | 173 | 8.2 | |
| Father’s education | ||||||||
| Junior high | 3,896 | 882 | 22.6 | 2,553 | 65.5 | 461 | 11.8 | <0.01 |
| High school | 23,901 | 6,029 | 25.2 | 15,591 | 65.2 | 2,281 | 9.5 | |
| Vocational | 9,936 | 2,610 | 26.3 | 6,472 | 65.1 | 854 | 8.6 | |
| Junior college | 2,252 | 664 | 29.5 | 1,415 | 62.8 | 173 | 7.7 | |
| University and higher | 27,418 | 9,495 | 34.6 | 16,357 | 59.7 | 1,566 | 5.7 | |
| Others | 139 | 44 | 31.7 | 87 | 62.6 | 8 | 5.8 | |
| Missing | 2,908 | 857 | 29.5 | 1,796 | 61.8 | 255 | 8.8 | |
| Mother’s working hours | ||||||||
| 0 hours | 39,276 | 10,860 | 27.7 | 25,147 | 64.0 | 3,269 | 8.3 | <0.01 |
| 1–19 hours | 6,663 | 1,874 | 28.1 | 4,225 | 63.4 | 564 | 8.5 | |
| 20–39 hours | 13,557 | 4,114 | 30.3 | 8,434 | 62.2 | 1,009 | 7.4 | |
| ≥40 hours | 9,592 | 3,353 | 35.0 | 5,613 | 59.4 | 626 | 6.5 | |
| Missing | 1,362 | 380 | 27.9 | 852 | 62.6 | 130 | 9.5 | |
| Father’s working hours | ||||||||
| 0 hours | 704 | 188 | 26.7 | 447 | 63.5 | 69 | 9.8 | <0.01 |
| 1–19 hours | 1,081 | 289 | 26.7 | 649 | 60.0 | 143 | 13.2 | |
| 20–39 hours | 4,468 | 1,267 | 28.4 | 2,803 | 62.7 | 398 | 8.9 | |
| ≥40 hours | 58,931 | 17,364 | 29.5 | 37,083 | 59.4 | 4,484 | 7.6 | |
| Missing | 5,266 | 1,473 | 28.0 | 3,289 | 62.5 | 504 | 9.6 | |
| Mother’s work type | ||||||||
| No outside work | 33,616 | 9,043 | 26.9 | 21,754 | 64.7 | 2,819 | 8.4 | <0.01 |
| Seeking employment | 3,264 | 983 | 30.1 | 1,986 | 60.8 | 295 | 9.0 | |
| Students | 118 | 31 | 26.3 | 77 | 61.4 | 10 | 8.5 | |
| Employed full-time | 13,328 | 4,792 | 36.0 | 7,726 | 58.0 | 810 | 6.1 | |
| Employed part-time | 13,580 | 3,827 | 28.2 | 8,641 | 63.6 | 1,112 | 8.2 | |
| Self-employed | 3,529 | 1,057 | 30.0 | 2,204 | 62.4 | 268 | 7.6 | |
| Domestic side job | 1,141 | 269 | 23.6 | 749 | 65.6 | 123 | 10.8 | |
| Others | 739 | 229 | 31.0 | 438 | 59.3 | 72 | 9.7 | |
| Missing | 1,135 | 350 | 30.8 | 696 | 63.4 | 89 | 7.8 | |
| Father’s work type | ||||||||
| No outside work | 79 | 21 | 26.6 | 53 | 67.1 | 5 | 6.3 | <0.01 |
| Seeking job | 520 | 131 | 25.2 | 330 | 63.5 | 59 | 11.3 | |
| Students | 51 | 17 | 33.3 | 33 | 61.4 | 1 | 2.0 | |
| Full-time | 57,036 | 16,838 | 29.5 | 35,808 | 62.8 | 4,390 | 7.7 | |
| Part-time | 808 | 222 | 27.5 | 510 | 63.1 | 76 | 9.4 | |
| Self-employed | 8,179 | 2,250 | 27.5 | 5,218 | 62.4 | 711 | 8.7 | |
| Domestic side job | 1 | 1 | 100.0 | 0 | 0.0 | 0 | 0.0 | |
| Others | 524 | 145 | 27.7 | 326 | 62.2 | 53 | 10.1 | |
| Missing | 3,252 | 956 | 29.4 | 1,993 | 63.4 | 303 | 9.3 | |
| Family income (1,000,000 JPY) | ||||||||
| Lowest quantile (0–<3.8) | 15,978 | 4,015 | 25.1 | 10,357 | 64.8 | 1,606 | 10.1 | <0.01 |
| Second lowest quantile (3.8–4.99) | 13,797 | 3,592 | 26.0 | 9,005 | 65.3 | 1,200 | 8.7 | |
| Second highest quantile (5.0–6.99) | 19,056 | 5,547 | 29.1 | 12,083 | 63.4 | 1,426 | 7.5 | |
| Highest quantile (≥7.0) | 16,887 | 6,070 | 35.9 | 9,884 | 58.5 | 933 | 5.5 | |
| Missing | 4,732 | 1,357 | 28.7 | 2,942 | 62.2 | 433 | 9.2 | |
| “Always” use of other forms of disciplines | ||||||||
| Explaining why this behavior was wrong | 58,561 | 17,515 | 29.9 | 36,719 | 62.7 | 4,327 | 7.4 | <0.01 |
| Saying “No” without any explanation | 15,186 | 2,893 | 19.1 | 9,707 | 63.9 | 2,586 | 17.0 | <0.01 |
| Allowing them to recognize their misbehavior by ignoring them | 981 | 182 | 18.6 | 489 | 49.8 | 310 | 31.6 | <0.01 |
| Letting them go out or put in a closet | 328 | 29 | 8.8 | 114 | 34.8 | 185 | 56.4 | <0.01 |