Do nationalities have distinguishable characteristics?

Just a curiosity I have. I have had a few people in my life either make a guess or tell me what nationality I am. Some say I look irish and others can't distinguish it but make an assumption. I am not offended by this. But for generally european/british/north american nationalities, do people of the same nationality have certain characteristic similarities that makes it possible to distinguish them from other nationalities? If so and your a mix, does the nationality characteristic that stands out more mean that is your dominant nationality in your gene pool?
For instance I'm ukrainian, metis, french, english, irish and possibly scottish. Does me looking more irish mean I have more irish in me?

I am not sure either.
I am a mix of Ukrianian, Lithuanian, German, English and a long time ago Irish.
My eyebrows are very Eeastern European - very arched and I have my Uukranian grandfathers hairline.
I am stong willed like my Lithuanian Mother, Grandmother and Great Grandmother.
My skin however is pale and pasty and I have rosey red cheaks so I have often been called and English Rose. But with my dark hair and grey eyes I think that might be the Irish bit too.
People do like to pigeon hole each other though. Being asumed thoroughly 'English' has often helped me when defending other ethinic minorities. I have lost count of the amount of times I have argued with xenophobic people who I have heard telling black or dark skinned individuals to 'go home' and asked them if I should 'go home to' as I am 1st generation English and the person they are abusing could well be 3rd of 4th generation English. It always shuts them up!
:-)

Holy, Just looking at your avatar I thought I was looking at me for a few secs.

When i was in germany i had people coming up and speaking to me in german thinking i was german and ive had people also mistake me as polish.

i think some nationalities can have "distinguishing" features ive noticed that from work that i could sit on the check-in desks (as i work for an airline) i found as people walking through the queues some of them you could guess what nationality they are just from facial features and sometimes the clothes etc...

its hard to pin point whats what i guess just when youve met as many people from different nations day in day out you kind of can pick out the differences some are blantantly obvious and others arent.

i hope this makes sense.

When we lived in Lincolnshire close to us there was an American college, you could always tell who they were, the girls wore really thick makeup with brown lip liners, whats with that? Then the boys, well they just looked a bit stupid really, badly done blond hair and shaped eyebrows, then shorts with long socks!

When I have been to America, the locals always think I'm Australian, not by how I dress but my accent, which is a quite broad Yorkshire accent mixed in with southern Lincolnshire (quite messed up really).

If a Brit were to see me, I think they would be able to tell straight away where I am from, total country bumpkin.

I'm not sure how this works to be honest. I don't have much far afield mixed blood but am a mix of English/Irish and Scottish. I have a brother and a sister and we are all completely different even though we have the same parents. I am average height, brown hair, straight as a di and fairly big build and very fair skinned. My brother is tall, slim and very blond? My sister is very dark, Much darker complexion too, with curly hair and large build? It is quite uncanny. I suppose it just depends how the genes mix themselves about on conception? I don't know if any are stronger (more dominant) than others although both my children have very light and curly hair (which there father has) where as mine is much darker and very straight? Coincidence or a more dominent gene? Who knows.
Did anyone see in the paper the other week a second set of twins born to a couple who are different races? The father is black (i'm not sure from where?) and the mother is white english. Both sets of twins, instead of the usual mixed race were born like their parents. ie. one was born "black" and one was born "white" (using inverted commas as they were obviously both mixed race) with all the features to match their skin colour. ie. lighter hair and eye colour etc for the "white" child and darker hair, and eye colour etc for the "black" child. It is very unusual for this to happen and even stranger for it to happen twice within the same family! A very interesting topic though! Xx