There's a great scene in the 1984 comic movie All of Me (starring Steve Martin and Lily Tomlin) in which the Swami (who's been brought to America to perform this weird soul-transference ritual, but who knows nothing of life in the west) is exploring his hotel room. He happens to flush the toilet, and is rather startled and confused by the weird noises the thing makes. But right at that moment one someone calls the hotel room (trying urgently to reach one of the other characters), and the phone rings. The Swami looks up, and the light of comprehension goes on: so he immediately flushes the toilet again... and of course, the phone gives another ring. So he happily flushes a third time, and the phone gives another ring, and so on....
This is an example of what people mean when they say "Correlation is not proof of causation." Of course, normal people don't say stuff like that in everyday conversation, but if they did, this would be an example of what they mean.
Of course, that doesn't keep us from speculating. If we see A happen a lot, usually followed by B, it makes us suspect that A has something to do with B. If the correlation is strong enough, it usually means that there is some kind of causal mechanism. The trouble is that we tend to jump to conclusions before we have a meaningful sample. After we've seen A and B happen together two or three times, we tend to start thinking that A and B are linked--even though there's still a good likelihood that it's a false correlation, caused by random chance.
So why do I bring this up?
In part, that's because I'm not a normal person, a la Paragraph 2.
But, Tonya observed a pattern today that is simultaneously really annoying, and downright hopeful. You see, Tonya and I have been considering trying for a fourth kid. After all, we really like the three we have, and we've decided that we could really use a little more chaos in our lives.
So here's the annoying pattern. Every time Tonya has gotten pregnant to date (with all three kids, and with the pregnancy that we miscarried), she has always come down with some hideous feverish plague of some sort within a month or so before conception, that causes her to lose any interest in food for at least a week. Every time, her weight has taken a huge drop within the month before conception--and this isn't the kind of weight loss that one feels good about. (Tonya was one of those women who as a young lady had trouble keeping weight on--and before you ask: no, she did not consider that a blessing.)
So, now that we're trying to get pregnant again, Tonya has come down with some kind of evil bug that's pretty well laid her out flat. The very smell of food--the mere thought of food--is turning her stomach. She tried to take the kids to the library today, but thought better of it just as she was approaching the library door--so they dropped the books off in the depository, turned around and came straight home. She tried to do her nails today (since the girls wanted theirs done too)--and the smell of the polish nearly wiped her out after she'd only finished one hand. She had no dinner; only a little water to keep herself hydrated.
Now, there is no rational reason to think that this sickness presages another little bundle of joy. I am completely unaware of any reasonable mechanism that might link a nasty bug and sudden loss of weight with fertility. But darn it, when something as yucky as one of these bugs comes around, it's very tempting to reach for any reason at all that can possibly justify the suffering. After all, Tonya had this stuff happen to her four times already just before getting pregnant; why shouldn't it happen like that again?
As I've said before, reason is overrated. :-)
And do keep Tonya in your thoughts and prayers.