What are some reasons for homophobia besides those based on religious beliefs?

Apparently most Americans who oppose gay rights are religious conservatives or ultra-conservatives, and I think that’s true for many people throughout the world.

However, if I remember correctly, homosexuality was illegal in Iron Curtain countries such as Cuba (perhaps it still is there), and the Soviet Union.

What was their reasoning or what were their issues regarding homosexuality?

Does it seem to you that more men than women are anti-gay?
If so, why do you think that is?

It does to me, but I know there are a least a few women who are, such as Anita Bryant.