This is a late reply because I missed this until now, but if you accept the typical parameters of a statistical thought experiment, you should assume that the p

This is a late reply because I missed this until now, but if you accept the typical parameters of a statistical thought experiment, you should assume that the permutations are equally likely. The real world nastiness of biology and society fouls that up, but thought experiments like this are never intended to be about not picky real world details, boy/girl is always assumed to be a coin flip. (Not to say that real world results are not interesting as well) And there are a half dozen arguments in this thread that claim to disprove this result even if they accept the coinflip hypothesis - it's really those that I take issue with.