Why are spirits typically 40% ABV?

Question

I live in France. I've found that at least cheaper (supermarket) spirits are almost always exactly 40% ABV. You can find stronger if you buy more niche or expensive alcohols like Chartreuse, but the vast majority seems to be precisely 40, unlike say wine or beer which varies more smoothly.

Is there a reason for this? Is 40% the legal minimum to be able to call something whiskey or vodka, for instance? Or am I just flat wrong, and there's no statistical trend towards 40%?

I realize the correct answer may vary from country to country. I'll be happy with an answer covering any "comparable" first world country (let's just say English speaking countries or West Europe, for simplicity).

Answer 1

There is indeed a EU Regulation No 110/2008 about "the definition, description, presentation, labelling and the protection of geographical indications of spirit drinks" which prescribes the minimal ABV for different spirits and it happens to be about 40%.

So

• the minimum alcoholic strength by volume of rum shall be 37,5 %.
• the minimum alcoholic strength by volume of whisky or whiskey shall be 40 %.
• the minimum alcoholic strength by volume of vodka shall be 37,5 %.
• with the exception of ‘Korn’, the minimum alcoholic strength by volume of grain spirit shall be 35 %.
• the minimum alcoholic strength by volume of wine spirit shall be 37,5 %.

and some more.

PS. The Vodka myth may be of interest for you too.