Some years ago, when my grasp of German was at a level of competent-but-not-idiomatic, I used the word Selektion – I can’t remember the exact context, but it may have had something to do with the British system of university admissions compared with the German – and was taken aback by the reaction of the people I was talking to. “You can’t used that word! Yes, it means ‘selection’, but that’s not what it means…” Because the Selektion of people into different categories is what happened on arrival at concentration camps; if you’re going to talk about dividing people into different categories, for example with admissions to university courses with restricted numbers of places, you definitely need to find a different word for it.
It was clear that, at least for these people – I’ve carefully avoided the word ever since, to be on the safe side, so don’t have any further evidence – ‘Selektion’ was unavoidably entangled with historical and political issues; not that every usage was deliberately evoking the horrors of the past, but that it could evoke such a reaction in the hearer. I can imagine (I haven’t checked) that there are people who employ the term precisely in order to provoke such a reaction, with a degree of deniability; but accidental usage, except by ignorant foreigners who don’t know any better, could only be because someone hasn’t thought things through adequately. You wouldn’t use the term ‘Selektion’ in the title of an academic conference, for example, unless you were either discussing the actual historical topic, or were being explicitly provocative.
Do Germans experience a similar feeling of shock or uneasiness when they encounter ‘Selection’ in English – in the context of university admissions, or boxes of chocolates? I would imagine that they might well do – but would recognise that this is essentially their issue, that the English usage is, almost certainly, entirely innocent of the cultural and historical associations that they cannot ignore. In some instances, this might not be true – an academic conference on 20th-century German history that used ‘Selection’ in the title would be reasonably be suspected of deliberate evocation (even if not provocation), or open to accusations of ignorance and thoughtlessness. But that’s because there are specific reasons why one can assume some degree of knowledge of the connotations of the equivalent term in German, even in a different cultural context; someone who objected to the name of Cadbury’s Selection Box would rightly be ridiculed.
Context is key. On the one hand, there’s a recognition that words cannot be abstracted from their wider cultural context and stripped of their associations, even if that’s the writer’s sincere intention. On the other hand, words don’t necessarily carry their associations with them into a different cultural context, even if that’s how someone from the original context will instinctively read them. To take a concrete example, the subject of a recent flurry of argument on the Classicists email list, in a US context the word ‘undocumented’ is inextricably associated with the specific plight of Undocumented immigrants (movingly discussed by Dan-el Padilla Peralta). I can well imagine that it’s now impossible to use the term in the US without evoking this theme, or without revealing oneself as naive and thoughtless (I’ve no idea what the consequences may have been for established phrases like ‘undocumented feature’).
How far do these associations extend beyond that context? The term ‘undocumented’ is used in the UK in the context of immigration, but I wouldn’t say that it had the same cultural resonances; that is to say, it’s obvious what it means in discussions of immigration or when used in relation to someone born outside the country, but simply seeing the word ‘undocumented’ in a different context doesn’t instantly bring to mind the topic of immigration, let alone the specific topic of immigration in the US. Artefacts may be undocumented. Historical events may be undocumented. The use of Undocumented as the title of an academic conference about ancient documents may indeed be a deliberate reference to the US situation, but I’m not convinced that it can only be a deliberate reference to it.
In brief: language is always political. But there is not yet a homogeneous global political context in which language is always political in exactly the same way everywhere.
Sphinx 
When I travelled in Germany, people almost always answered me in English, but since they gave me the answer I asked for, I figured my German was good enough they understood me but not fooling anyone at all.
This is a real challenge in learning a second language. You always have the propensity to stick your foot in your mouth. I agree that “undocumented” is a weighted term in the US, though it is still used regularly for political effect. Your discussion of “Selektion” makes me think that perhaps language is like Weather, and certain terms, like certain storm names, are essentially retired from usage as too profane or ugly. In the US, the “n” word comes to mind. “Undocumented” May join its ranks someday, as something simply not spoken or used, but I don’t think we are there yet. Sehr interessant!
It depresses me a little that you analyze an issue so closely, then round your post off with the slack conclusion that language is “always political”. You do establish that words will often have intended or unintended resonance beyond the dictionary meaning, which seems to be the more useful finding.
BTW, I do not think “undocumented” is off-limits in contemporary North American Englsih. I think you could accuse someone of making an “undocumented assertion” without invoking the immigration issue. But maybe not – I don’t deny that terms can be politically hijacked and driven thereby out of polite or neutral use. But this doesn’t make language “always political”.
Okay, yes, absurdly loose formulation – I was focusing more on the second half, that a word like ‘undocumented’ can’t be separated from context, including political context, but that context isn’t universal.
The word ‘Selektion’ is used in German however often more scientifically (for example in biology). But the normal German word is simply ‘Auswahl’ and more useful commonly as it sounds not so stealthy Latin-academic like ‘Selektion’.
It suppose it really depends on the context. The word “Selektion” ca be used without problems in the context of biology (it is part of the scientific terminology in that case). I am not a native speaker of English, so thanks for pointing out to me that “undocumented” might have some ngative connotations in some context. I have actually only come accross that word in the context of computer programming (e.g. one should avoid using undocumented interfaces (e.g of operating systems) in programming because they might be changed without notice from one release of a software to the next). So a word that is taboo in one context might be a normal part of technical terminology in another.
With reference to both your conclusion and selection, you ought to look across the Channel. Sélection, in French, although it can be extensively used, mostly appears in the public language with reference to entry into university. Up to now, there has been none, other than ending high-school with the baccalaureate., about 60% of students giving up studying during the first two years. Obviously not a very efficient use of available means. But there is strong resistance amongst students and teachers to the introducing of « sélection » viewed as socially regressive and politically objectionable. Although the system is finally moving in that direction, a wealth of semantic imagination goes on display to avoid using the wretched S-word.