Originally
posted by
Dibs Ludicrous:
they live longer and healthier now, so we should have more children per couple, not less.
Negative. Life expectancy has nothing to do with human birth rates. Once a woman reaches menopause she ceases to have children, irregardless of how old she is. Your statement only works if couples continue to have children throughout their entire lives, which is not the case. Furthermore, the rate of crippling birth defects or other genetic problems (i.e. Down Syndrome) dramatically increases with women over 30 years of age. The majority of children are born to women in their 20s/early 30s. In comparison to say, a mouse, who may be fertile for most of their short lives, humans spend a smaller percentage devoted exclusively to giving birth and procreating. This is a throwback to earlier times in history when the average life expectancy was 30-40 years of age. During that time, it could reasonably be expected that the percentage of the population 18 and under was far higher, not because couples were producing more babies, but because the dilution effect that Qzjul pointed out wasn't occurring. With the advent of modern medical techniques, people are living longer, driving down the percentage of the population under 18.
TLDR: It's fine and you're reading into the statistic wrong. What Qzjul said.