This (watch closely, you might learn something!)... is Scotland:
And the Highlands are a region of Scotland. Definitions vary, but restricted to the council area itself, these are the highlands:
(Other definitions might include some bordering territories, the Outer Hebrides, Shetland, Orkney, the Grampian mountain range and Cairngorms National Park -Scotland invented national parks [like everything else]- and to its furthest extent, anything north from the central belt)
Now, the Highlands are the birthplace of a lot of traditional Scottish culture, for example, the caber toss.
The joke was, that people from the Highlands are generally very "manly" and (watch closely: here comes the joke) therefore opposed to homosexuality. It's a bad generalisation joke that you might hear, for example "A Russian woman is more manly than a Belgian man", or something like that.
Hope you learnt something about foreign culture today :)
Edited 11/27/2015 22:03:46