Extensive body tattooing looks a mess, especially on necks and faces and especially on women.

I agree.

And I was generalising.

Mental health covers all aspects of internal data management and associated problems, or what we might perceive to be problematic irrational behaviour.

And for sure, "normal" is only an assumption relative to an imprecise and variable standard. Well exemplified by the social acceptance of extensive body disfigurement as something of a norm.

Eh, I hear getting a tattoo causes some pain,

And I suppose tattoos 'are often seen by a portion of society as disfigurement,

So I suppose 'some individuals might get tattoos, with intention or vague feeling of self harm.

Limited body space, I'd think though.

I suppose some people might get tattoos as a form of expression, maybe people with more of a need for expression, are more emotional/unstable.

Though it's not 'bad to have emotions.

Though tattoos are also simply popular in some cultures, whether in,

Institution such as American Military,

A People, such a  Maori people of New Zealand,

Aesthetic subculture, such as Goths.

Though that's not to say all people in military, Maori, or Goths have tattoos, but they're more normal in some societies, I think.

I've also known some people who got tattoos to cover up previous cutting that they did.

Tattoos don't 'mean a person is abnormal though, to my thinking,

But it 'is often an unusual choice, that might say something about the person.

A very balanced response.

Though, I think that all tattooing is unnecessary, the odd concealed badge of honour or bowing to trend is OK.

I was particularly referring to extensive, unconcealable and deliberate body tattooing, which clearly and perceivably disfigures. (See RM's extreme examples) 

Look at me, do I look amazing?

No, look at you, you look a f****** mess.

And you will continue to look a mess until the day you die.....So why would you do that?

It's only my opinion, but I agree with you. Tatoos, in my opinion, should be symbolic ( like somebody's last heartbats, the name of a family member or something very important for you) or a very small tatoo like a flower. I don't find tatoos atractive.

There are a lot more distinguishing features of race than skin color. Height, hair color and type, and facial structure are all highly influenced by ethnicity. It would still be fairly easy to pick out an Asian in a lineup of your theoretical tattooed "blacks."

Also, why is that thought unnerving? Would it be so bad if everyone looked the same? It doesn't stop people from hating each other for their religion, politics, place of birth, taste in music, etc., but people choose to advertise those. It's one of the reasons Nazis put badges on Jews and homosexuals; it's a lot easier to oppress and abuse someone after you put a target on them. If I decided that I didn't care what people think of my religion, I could wear a shirt that says ATHEIST on it. Black people don't get to take off their BLACK shirts.