Brett & Kate McKay write at The Art of Manliness:
As you make your way through the photos below, many of you will undoubtedly feel a keen sense of surprise — some of you may even recoil a bit as you think, “Holy smokes! That’s so gay!”
The poses, facial expressions, and body language of the men below will strike the modern viewer as very gay indeed. But it is crucial to understand that you cannot view these photographs through the prism of our modern culture and current conception of homosexuality. The term “homosexuality” was in fact not coined until 1869, and before that time, the strict dichotomy between “gay” and “straight” did not yet exist. Attraction to, and sexual activity with other men was thought of as something you did, not something you were. It was a behavior — accepted by some cultures and considered sinful by others.
But at the turn of the 20th century, the idea of homosexuality shifted from a practice to a lifestyle and an identity. You did not have temptations towards a certain sin, you were a homosexual person. Thinking of men as either “homosexual” or “heterosexual” became common. And this new category of identity was at the same time pathologized — decried by psychiatrists as a mental illness, by ministers as a perversion, and by politicians as something to be legislated against. As this new conception of homosexuality as a stigmatized and onerous identifier took root in American culture, men began to be much more careful to not send messages to other men, and to women, that they were gay. And this is the reason why, it is theorized, men have become less comfortable with showing affection towards each other over the last century. At the same time, it also may explain why in countries with a more conservative, religious culture, such as in Africa or the Middle East, where men do engage in homosexual acts, but still consider homosexuality the “crime that cannot be spoken,” it remains common for men to be affectionate with one another and comfortable with things like holding hands as they walk.