Table 1. Summary statistics for OLS regressions.
| Dependent Variable | Intercept (SE) | Slope (SE) | Adj Rsq | P value | df |
|---|---|---|---|---|---|
| industrial populations | |||||
| Births per year | 0.214 | −0.365 | 0.522 | 3.67E-21 | 120 |
| (0.237) | (0.032) | ||||
| Mortality under age five | 10.279 | −0.969 | 0.684 | 8.56E-32 | 119 |
| (0.448) | (0.060) | ||||
| Life expectancy* | 3.284 | 0.124 | 0.420 | 3.41E-16 | 121 |
| (0.098) | (0.013) | ||||
| Age at first reproduction | 2.447 | 0.095 | 0.611 | 2.94E-22 | 99 |
| (0.057) | (0.008) | ||||
| Age at menopause | 3.705 | 0.025 | 0.413 | 5.67E-04 | 21 |
| (0.048) | (0.006) | ||||
| Age at menarche | 2.844 | −0.032 | 0.259 | 1.93E-05 | 58 |
| (0.053) | (0.007) | ||||
| Reproductive delay | −0.323 | 0.341 | 0.695 | 3.02E-15 | 52 |
| (0.237) | (0.031) | ||||
| Net reproductive rate | 2.304 | −0.302 | 0.515 | 1.37E-18 | 106 |
| (0.211) | (0.028) | ||||
| Reproductive lifespan** | 35.760 | −1.359 | 0.300 | 7.34E-03 | 18 |
| (3.521) | (0.450) | ||||
| nonhuman primates | |||||
| Maximum lifespan | 2.380 | 0.271 | 0.507 | 6.07E-17 | 98 |
| (0.079) | (0.027) | ||||
| Age at first reproduction | 0.035 | 0.445 | 0.730 | 5.49E-29 | 95 |
| (0.082) | (0.028) | ||||
| Reproductive delay | −1.338 | 0.321 | 0.159 | 1.13E-03 | 56 |
| (0.285) | (0.094) | ||||
| Age at menarche | −0.306 | 0.495 | 0.685 | 9.38E-22 | 79 |
| (0.112) | (0.037) | ||||
| Reproductive lifespan** | 7.980 | 4.600 | 0.319 | 1.05E-08 | 83 |
| (2.184) | (0.724) | ||||
| mammals, excluding primates | |||||
| Births per year | 2.312 | −0.376 | 0.662 | 1.08E-67 | 278 |
| (0.064) | (0.016) | ||||
*A nonlinear function is more appropriate for this variable, see Figure 2C.
**Crude estimate, see Methods, and not log-transformed.