In a formal academic paper, how would one mention a decade: "1960s" or "the sixties" or "the nineteen sixties"?

As I have come to believe, you only write out the one digit numbers. So 0–9 would be written out, but anything after that you write in number form. Also, “the sixties” is informal so don’t write that or “60’s”

1960s

I think you’d be on much safer ground, considering that this is a “formal” academic paper, to refer to an exact term: “From Kennedy’s Inauguration in January of 1961 until Nixon’s election in November of 1968”, for example. Try to reference the exact beginning and end with specific dates (and occurrences). “The 1960s” is pretty vague, after all, if it’s not all of the 60s.

You can write it as “the 1960s.”

I’d say Sixties or 1960s are fine, though 1960s will be more enduring. What will your paper look like in 2075?

But sticking to one or the other is probably the best way to go. Be consistent.

pokes @Jeruba to see if she’s OK… she’s been “crafting a response” for far longer than it seems this question would necessitate. :-/

If you are using a specified style sheet (such as APA or MLA or the Chicago Manual of Style), follow its prescribed treatment of dates.

I have used publishers’ house style sheets that called for “the 1960s” and “the 1960’s” and also “the nineteen sixties.” Chicago approves “the 1960s” (no apostrophe), and that is what I would edit it to if I were your editor. In a less formal context, “the sixties” would be fine.

Thanks, @heakat. Sorry, the timer went off and I had to get the lasagne noodles out of the pot and put the lasagne together. It’s in the oven now.

@Jeruba: Yum! What time shall I arrive for dinner? Should I bring dessert?

In half an hour, and we won’t have any room for dessert. I used the large pan. Some red wine would be nice, though.

@bolwerk is correct in pointing out that whatever you do, you must be consistent, and that means not only for the same expression wherever it occurs but also for any analogous expression. The trick with consistency is not just to do the same things the same way but to recognize all the things that belong in the same category.

I would use a specific year. But if you must generalise then I’d use ‘the 1960s’.

Wouldn’t “Nineteen-sixties” necessitate a hyphen? or is that archaic now?

@Jeruba: Pesky Blizzard! I don’t think I can make it on time. Enjoy a corner piece for me!

If you’re writing a formal academic paper your school or professor should have provided you with some guidelines, some kind of reference. MLA v.s. APA style for example. Then you should follow whatever standards are outlined in those.

@Seek_Kolinahr, I would have thought so too, but Chicago has it without the hyphen.

Experts agree that single numerals should be spelled out. Larger numbers are a bit more problematic. There is some disagreement, and if there’s a book of style governing the institution you are submitting the paper to, by all means check that.

But in general, experts say larger numbers that can be expressed in one word should be written out. So you would use ‘twenty’ for the numeral 20 but switch to numerals for ‘21’, since it would require 2 words. Centuries and decades should always be written out.

@ETpro, dates are typically treated differently from ordinary numbers. Many publishers and style authorities say to spell out numbers from one to ten and use numerals from 11 on up. A technical document might use numerals in all cases; a more literary and/or traditional one might write out longer numbers in words.

Style is a matter of choice among acceptable alternatives. The main things are (a) to follow the prescribed style or (lacking an assigned guide) the one you have chosen and (b) to be consistent.

@Jeruba I think that’s pretty much what I said. Follow the requested book of style if there is one. For decades, write them out. For other numbers, styles vary, but the guidelines I listed are what most style experts recommend.

I’d go with 1960’s myself but I don’t often wright anything official. If there isn’t a guideline to the style you are using 1960’s should work.