Some of us have more chins than others, but why do we have chins? Other creatures get along without them.
Ther’re a natural biproduct of the kind of FACE we have, and the type of body it’s perched upon.
All mamals with similar structures - mostly simian beings - have chins, or a semblance of a chin to my knowledge.
Yer pal,
Satan
They do? Chimpanzees have a sort of round jaw, for instance.
Chin/Jaw Jaw/Chin. One in the same. I just checked both of our cats, and they’ve got chin/jaws too. Helps with chewing and talking/meowing. I suppose you could have a jaw and no chin if your mouth was located in the middle of your face, between the nose and eyes, but nature saw fit to do it the way it is now.
Therealbubba
Well, from what i heard on a TV show on the Discovery Channel once, all mammals and mammal like animals (me thinks) have chins, but humans are the only ones with forward protruding chins. Don’t know the reason, but that’s what I’ve heard.
‘The beginning calls for courage; the end demands care’
Ok, so now we are looking for forward protuding chins.
Some links to primates that I found. Should show the weak chins of apes: http://www.skullsunlimited.com/PhiladelphiaZoo.htm http://www.neanderthal.de/ http://www.primates-online.com/
I think that had the best side view of an ape http://www.bergen.org/Smithsonian/prigal.html
No none knows why we have chins.
Frankly, I’d be more interested in why they call them chins.
Quote:
Frankly, I’d be more interested in why they call them chins.
Easy one…'cause they’d already used “wang” for something else.
Browsing the Peking phone book.
JB
Lex Non Favet Delictorum Votis
We have chins so we have something to keep up when misfortune befalls us. As JBENZS alluded to, the old expression, “Keep your wang up,” became, uh, problematic when the English language developed slang.
Livin’ on Tums, Vitamin E and Rogaine
My WAG is that we have chins because chins were an attribute that the opposite sex found attractive. Slowly, over the millenia, selective breeding creating humans with larger chins.
Or maybe that’s what happened with wangs …
Then Jay Leno ought to be voted Sexiest Man Alive.
Oh oh…where’s this going…and where is Dr.Fidelius with a good WAG?
If we didn’t have chins the people who make chin staps would be unemployed. 
Why forward protruding chins?
Neotony.
(Longer answer available upon request)
Pigs and humans alone have chins (it’s not just the forward jutting – there’s a reinforcing bone there that other critters don’t have).
The only obvious connection would be an omnivorous diet, since one rarely sees pigs boxing.
John W. Kennedy
“Compact is becoming contract; man only earns and pays.”
– Charles Williams
I respectfully disagree with the pig/human extra bone idea.
All mammals have two bones in their lower jaw the dental bone (the chin) and the mastoid bone (the bone that connects to the skull). Reptiles, conversly have four bones in the lower jaw (the dental bone IS one of the four). This is a primary way paleontologists can distinguish between reptile fossils and mammal fossils.
So all mammals have the dental bone (Pigs and humans don’t have an extra “reinforcing” bone). Incidently, I don’t remember my pig skulls having a forward protruding dental bone…I’ll have to dig them out and look more closely, but I think they didn’t.
The whole question of why we have chins is silly. We have them to support our lower teeth, there’s no other reason.
The answer to the question of why ours protrude and most others don’t is still
Neotony.
If the question is why are our chins shaped that way then part of the reason may be our brains. In certain humans and most animals the jaw muscles take up a large part of the space inside the skull, but that’s ok cause their brains are small. A good example would be the alligator’s head.
Another reason is, of course, our diet and posture. Our chins stick out because our head is not pointed along our bodies as most animal’s head are. Also if you look at early humans their chins are very different, probably because of changes in diet.
Oh, don’t I wish.
You say “cheesy” like that’s a BAD thing.
A protruding chin is the unique hallmark of Homo Sapiens. Neanderthan man, Homo Erectus, et al, have a rounded chin. I think that it’s more a case of the rest of our lower jaw having shrunk and receded, leaving that knob of bone sticking out.
Okay, I give. I’ve tried looking it up with no result. What the hell is neotony?
Bluecher!