Good article Shani! Stats are fun to play with but people DO need to question what they are reading more often and look at what they AREN’T being told.
70% of families with 4 children have at least 3 of the same gender.
When I heard this tidbit over lunch a while ago I found it fascinating. You would think (or at least I initially did) that the larger percentage would belong to families with 2 boys and 2 girls. I was randomly thinking about it this morning when, like a lightening bolt to the brain I realized I had been a complete idiot. I shall explain.
Your answer on this is absolutely correct but there is also a 2nd explanation for this: Parents have a choice in how many children they have.
The odds of a first child being a boy/girl are, as you said, right near 50/50. The odds for that 2nd child are also 50/50.
But, parents are more likely to have a 3rd child if the first two are both boys or both girls (45%) than they are if the first two are 1 boy and 1 girl (39%).
And that is followed further in that parents that have 3 children of the same gender are more likely to have a 4th child (28%) than parents that have 3 children of mixed genders (20%).
So parents with mixed gender children are less likely to ever qualify as one of those “families with 4 children” to begin with. If the first 2 or 3 children are of mixed genders, they are much more likely to stop having children so “families with 4 children” isn’t a random even distribution to begin with.
I only mention that because it is also important to keep in mind that stats have to be kept in context too!