Here is one for you guys to ponder. There is a crazy discussion on on Boston board sparked by blatantly Anti-Semitic remark of one of the participants. By now the discussion itself kind of fizzling out.
In the course of the exchange one of the respondents mentioned that Jews are all those who believe in Judaism, i.e. it is a religion and religion only, like let's say, Christianity, Islam, Buddhism and so on and I took issue with that citing notions of "Jewish looks" and Jewish cultural upbringing. Obviously it's not a race as in White, Black, Asian, etc. but is it an ethnic group like Italians, German, Chinese, etc? I think it is.
I wonder how many think one way and how many the other. I wish I could create a poll here but... btw, can I? Maybe I'm missing something.
who looks like Arnold Horshack
There are many meanings, all correct in their context.
Obviously, it is a religion. THose who believe the teachings are Jews.
But I don't believe and haven't been to temple in about 40 years. But I don't mind when people say I am Jewish. In one sense I am. In others, not.
Likewise, it is a culture. Actually, many related cultures. Eastern European Jews are different in many cultural aspects from Mediteranean. My family is German/Russian Jew and I was confused the first time I went to the Seder at the house of a college friend whose familly was Morocan. Music, food, art, and many other cultural aspects are different. But they are Jews. (Try this on for size, the Ethiopian Jews that had been cut off for centuries and evolved very different cultures. )
Yiddish is the language of Eastern European Jews, but Jews from the Separdich branch tend to speak Ladino. If you go to the synagogue in Istambul they talk Turkish and Ladino.
"Jewish" cooking usually refers to Eastern European. There is a Jewish literature, and music.
THere are a lot of other defintions, all correct in their own context.
The same is true of other religions. There are many people who say they are "Christian" who haven't been to church in 20 years, or only go on Easter and don't believe in the divinity of Christ. There is also a "Christian" culture - think art - St. Mark's and 10,000 other art objects in Italy, just to start.
(On a side note, this is why it is not to outrageous to say Obama is a Moslem. According to 1 billion people, Moslems, not Tea-Baggers, he is Moslem because his father is. If you are using the defintion of belief, he is not. If you use the defintion applied by Moslems he is. If you use cultural he is not.)
Interesting and in many ways true. But perception still exists about Jewish looks, at least in Europe and actually in America too. And make no mistake with your background chances are you'd be recognized in both Russia and Germany and maybe even here in the States, as a Jewish-looking man which admit has nothing to do with religion.
As for Obama, well, sure. But you may call him Muslim based on such a criteria but you'll never call him Muslim-looking 
There is just no such a thing unless one dresses up in the certain way. Jewish-looking however could be your face and therein lies the difference.
The perception of "Jewish looks" is because many "Ashkenazi" Jews - the term for German Jews, also used for Eastern European - are in fact related. In fact, there was recent genetic research that showed a close relationship between many Askenazi Jews.
On the other hand, the Mediteranean Jews are not as closely related, and "don't look Jewish," but everyone thinks of the more prominent Ashkenazi, because that was the group that moved here in the biggest numbers in the late 1800 through early to middle 1900's.
There is no "Moslem" apearance because it covers a huge geographical area. When the Moslems spread out in their first few hundred years, they were very much into conquest and forced conversion - or, at the very least, "strongly encouraged" conversion.
In fact, there is no Moslem dress, because that is regional. Even the blue burkas of Afghanastan are different from the black of Iran. Many Moslems do not require veils, etc.
It is even local. When I was in Syria about 15 years ago, the guy who was showing me around could point to people and say where they came from. Much the same way we can hear New York v. Texas accent, or how someone in California garb may stand out in Russia, even though they both may be white Christians.
(One of my first majors was anthropology, so it is a subject I tend to go on about. Sorry.
I don't know enough about Mediterranean Jews to say whether local no-Jews could differentiate between themselves and their Jewish brethren. I presume that nowadays the number of Jews living in North Africa is numerically so negligible that I doubt they would stand out among the rest of the population unless dressed in certain way.
As for Southern Europe, well, I'm not sure about other countries of Southern Europe (I haven't been there) but in Italy and France, make no mistake the locals know the difference. So even as Mediterranean Jews go it's not all that simple.
-- Modified on 9/17/2014 7:19:23 PM
Of course, things change and people move.
I am talking about traditionally. Obviously, after WW II, the number of Eastern European Jews living in Israel grew. Likewise, the Mid-East Jews have left their old homes. There used to be a good size community in Syria, but when I went to Damascus about 12 years ago, the synagogue was bordered up and the neighbors said that was where the Jews had been.
The same is true in Iran, Egypt, and other countries. (I have visited synagogues in about 15 different countries, including Lebanon, Turkey and Egypt. Couldn't even look inside the abandoned one in Damascus.)
Those Sephardic are now mixing with Ashkenazi, with predicable results. There is a cultural genocide going on in a very real sense in that sub-cultures are disappearing.
The same is true in Italy and France. Polish and Eastern European Jews are moving in. (although they aer moving out now. The number of French Jews who have fled France is very upsetting. In fact, many Swedish Jews no longer feel safe.)