Why Do The Odds Have More ʙᴏʏs Than ɢɪʀʟs
Most human parents-to-be assume that with an equal chance of conceiving a ʙᴏʏ or ɢɪʀʟ. But in reality, the odds aren’t even – for every 100 ɢɪʀʟs born, the world gains about 106 baby ʙᴏʏs. Currently, that skewed s.e.x ratio comes out to roughly 10 million more baby ʙᴏʏs than ɢɪʀʟs born worldwide each year. There are some countries where human meddling stacks the odds even higher in favor of ʙᴏʏs, but that doesn’t explain the fixed odds everywhere else. The intrinsic ʙᴏʏ/ɢɪʀʟ ratio is ʀɪɢɢᴇᴅ by Mother Nature.
So by the time kids grow up and reach baby-making age, the ratio of ᴍᴀʟᴇs to feᴍᴀʟᴇs is just about 1 to 1. But the likelihood of a ʙᴏʏ even making it to birth is also influenced by his mom’s living conditions during pregnancy. For example, when a ᴍᴀssɪᴠᴇ Fᴀᴍɪɴᴇ struck China in the early 1960s, the relative likelihood of having a son suddenly dropped – until the famine ended. And male Americans born to billionaires seem to have higher than average odds of fathering sons. Somehow, Fᴇᴍᴀʟᴇ biology suppresses ʙᴏʏs’ survival in the womb during tough times and boosts it when times are good.
So male offspring are a bigger ʀɪsᴋ in general – at all stages they’re more likely to ᴅɪᴇ, and even if they live they might not reproduce. But when times are good, ʙᴏʏs potential to father lots and lots of babies make them a biological ʀɪsᴋ worth taking.