Apple
Apple's new iPhone 5S has a fingerprint security detector, called Touch ID, which unlocks the phone only if it detects your fingerprint.
Immediately, people wanted to know — if someone chopped off your finger and stole your iPhone 5S, could they use the severed digit to unlock your phone? (The answer is no, apparently, but the question is even more ghoulish once you consider that its premise is that safeguarding the phone is more important than the finger.)
Of course, there's an even more crucial question that ought to be asked before you get to the iPhone 5S:
If someone — kidnappers, for instance — is going to chop off one of your fingers, which finger should you sacrifice? This actually happened to a British man kidnapped in Syria this year, so it's not simply a fanciful dilemma.
Many people get this wrong. They assume that the little finger, the pinky, is the one to say goodbye to.
Jim Edwards / BI
The author and his mom on a very cold day, watching Liverpool F.C.
I asked my mom, a retired doctor who practised surgical anesthesia for years in the Liverpool, U.K., area, which finger you give to the kidnappers. In terms of patients with actual severed fingers, she's seen a "couple of dozen fingers maybe, and an ear" in her career.
She says you want to give up the first finger on the hand you don't use for writing.
A lot of people think the first, pointing finger is the most important one they have. Wrong! Once it's gone, the other three compensate for it quite well. The second finger, for instance, is already pretty similar to the first finger.
The pinky is actually incredibly important, and it's a keeper. Basically, the reason humans have "opposable" thumbs — the springboard of our evolution from being just another ape — is that the thing doing the most opposing is the little finger.
According to the assistant chief of hand surgery at the NYU Hospital for Joint Diseases, the little finger does a disproportionate amount of gripping, while all the other guys are its helpers:
The other three digits—the index, the thumb and the middle finger—they fine tune where the tool goes. So if you have your little finger amputated, you're going to lose a significant amount of grip strength when holding everyday small objects. When you talk about utensils—like knives and forks—most of that stuff is fine manipulation rather than strength, so you're typically using the other three digits. You use the thumb, the index and the middle fingers in order to hold a spoon, or to hold a fork, or even to hold a pen and write things.
Take this test: Try doing pull-ups without using your little fingers, and then do the same without your first fingers, and you'll get an idea of how disabling it is to lose the pinky. A New York Times writer described the experience in 2008. It's not fun.