> If you grew up poor with parents that weren't kind to their bodies and died young you'll probably do the same, marry someone who does the same and have kids w

> If you grew up poor with parents that weren't kind to their bodies and died young you'll probably do the same, marry someone who does the same and have kids who do the same. Considering that 90% of the population used to engage in manual labor on farms to provide for themselves, if your lineage never made the transition to non-manual labor like most of the developed world, genetics are probably a more likely explanation.