i'm sure this has been covered many times
with my un-scientific comparison:
22LR is better than nothing, better than a knife at distances longer than your arm
better than a 9mm, 40, 45, or 44? thats what the link says.
but my wrist tells me a 22 is almost like shooting a pellet gun
whereas my wrist tells me a 45 or 44 magnum seems like it would hurt a whole hell of a lot more than a 22
i'm sure the FBI and police do their own studies and select bigger calibers for a good reason.
Morning Stang.
I am neither supporting nor defending the article, merely sharing actual scientific study to fire up an age old argument.

Actually, I thought the articles were quite enlightening.
Remember, they were written to provide data about "stopping power" aka incapaciatation or submissivenouss, not termination, though fatalities per cal are noted.
The link says.better than a 9mm, 40, 45, or 44? If you read the initial article by Greg Ellifritz @ BFA
http://www.buckeyefirearms.org/node/7866you'll see the support for larger calibers by FBI and police by his statement " majority of these shootings did NOT involve shooting through intermediate barriers, cover or heavy clothing. If you anticipate having to do this in your life (i.e. you are a police officer and may have to shoot someone in a car), again, I would lean towards the larger or more powerful rounds."
And "If you want to be prepared to deal with someone who won't give up so easily, or you want to be able to have good performance even after shooting through an intermediate barrier, I would skip carrying the "mouse gun" .22s, .25s and .32s."
He also states...
" Is a .22 a good self defense round? According to the numbers,
it looks to be among the best in terms of stopping the threat. Add in the fact that it’s lightweight, low recoil and uses firearms that are ridiculously easy to conceal and you can see where a .22 caliber firearm for concealed carry
might be a winner.
Some emphasis was that shot placement (all data was based on head /torso shots) had more to do with "stopping power" than caliber size but " In a certain (fairly high) percentage of shootings, people stop their aggressive actions after being hit with one round
regardless of caliber or shot placement. These people are likely NOT physically incapacitated by the bullet.
They just don't want to be shot anymore and give up !" and "in the majority of shootings, the person shot merely gives up without being truly incapacitated by the bullet".

"Stopping power" vs the so called "one stop shot" or target termination.