There is definitely a "Jewish look," or several, in the popular imagination, and it has existed as a constant archetype in Europe and North America for centuries. The archetype has some basis in reality - many Jewish people, or those of Jewish ancestry, myself included, do possess some of the physical characteristics thought to signify Jewishness.
In the past, and to a certain extent in the present, the "Jewish look" has had very negative connotations, signifying sinister intentions, as in the anti-Semitic propaganda of Dreyfus-era France, or the Third Reich. It has also been a short-hand for physical features considered to be unattractive. Occasionally, on the other hand, it has been seen as more benign or even positive, signifying the work ethic and family values that Jews are assumed to possess. The "Jewish look" applies mostly, but not exclusively, to men.
Some aspects of the "Jewish look" emphasize racial and ethnic physical features that sometimes occur in Jewish populations. These include:
- A large and/or hooked nose with flared nostrils
- Black hair, often curly
- Thick eyebrows
- Long eyelashes
- A slightly swarthy complexion
- A heavy, jowly face which gets even more jowly with age
- Large lips
- A pudgy build
- Abundant body hair
- Large ears
Other aspects of the look are derived from cultural stereotypes. These are often contradictory, as the role of Jews in larger society has changed over the years. Some of these cultural signifiers are:
- A beard, often heavy and unkempt
- Heavy black clothing and hats (particularly among the Hasidim)
- Thick "Nerdy" glasses
- Pasty skin
- "Slick" hair and a suit with no tie in the style of a Hollywood producer
- Tan, leathery skin
- A "Jewish afro" of big, free hair
Contrary to popular perception, the physical traits listed above are not Eastern European in the slightest. Hang around Russian or Polish neighborhoods and you will not see much curly dark hair, olive-ish skin, thick eyebrows, or large noses. Indeed these physical traits have their origin in the Middle East and the Mediterranean. The ethnic heritage of Ashkenazi Jews, those that have historically formed the majority of the Jewish population of Europe and North America, is a combination of Germanic, Mediterranean, and Middle Eastern stock, and the fact that the "Jewish look" traits are possessed to varying degrees among Ashkenazi populations is a result of this.
Some prominent Jewish people with the stereotypical look are Ben Stein, Milton Friedman, Ben Stiller, Walter Mathau, Neil Gaiman, Ed Koch, Russell Feingold, Adam Sandler, Richard Feynman, Albert Einstein, Abbie Hoffman, David Schwimmer, Ron Jeremy and Shimon Peres.
Because the traits in the public imagination that makes one "look Jewish" are rather vague and also fairly common, many non-Jewish people are thought to be Jewish. This is often the case with people of Italian, Greek, or even Lebanese or Syrian ancestry, or of generally book-ish appearing people of any nationality, especially if they sport a beard or glasses.
Many people, mostly people who are of Jewish ancestry themselves, claim to possess "Jewdar," an ability to recognize someone as Jewish whether or not that person has the stereotypical traits of the "Jewish look." As someone who has this ability, I can testify to the fact that there must be some sort of common Jewish appearance beyond those of the stereotype. Whether it is a purely physical trait or some way of carrying ones’ self I cannot determine.