Where I suspect, like with Germany and Austria may be more of a matter of geography and history. Since I don’t know much about history for these nations, it’s best to look at geography and demography. Iceland’s isolated and volcanic. Norway’s closer to the Atlantic, Denmark to Germany and Sweden and Finland in the Baltic.
Sweden, Norway and Finland all have Sami populations, those predating the Indo-European Scandinavians. Iceland and Denmark don’t. (When you have Samis, there’re inevitably degrees of discrimination and marginalisation by the majority.)
Iceland, being volcanic and isolated from the rest of the world has little to no known ethnic minorities until recently whereas Sweden, Norway and Finland already and still do with the Samis. Sweden has numerically more people than Denmark but because the latter’s got less land area it’s more densely populated.
Norway ruled over Iceland and Norway itself used to be ruled by Denmark whilst Sweden ruled Finland. Now here’s something more trivial, Denmark begat Aqua (and White Horse). Sweden begat ABBA. Norway begat A-HA and Iceland begat Bjork. Ikea’s Swedish, Lego’s Danish.
I’ve yet to go to those places but I’ve quickly summed up the differences.
fynm 