The Secret History of X & O

An Investigation Into the Religious Roots of the Symbols for Hugs & Kisses

By Nadine Epstein for Moment Magazine

I grew up in a family wary of anything overtly Christian. My father transformed the expression “cross your fingers” into “star your fingers” because, as he used to explain, crosses are Christian and thus not for Jews. Yet at the same time, my mother taught me to write “x” and “o”—a kiss and a hug—after my signature. So deeply embedded was this English-language tradition that I am sure it never crossed her mind—she was a proper Jewish mom as well as the executive director of the Jewish Community Center—that the “x” might have anything to do with a cross.

I never thought about it myself until she passed away in 2012 and I began to emit streams of “x’s” and “o’s” like a binary love code in the countless personal and professional emails that consume much of my daily life. Suddenly I became curious about where these symbols come from, these ur-emoticons that English speakers of all faiths sprinkle so liberally across our correspondence.

The Internet abounds with origin theories of all kinds. I found visual explanations: that “x” resembles a kiss; “o” looks like an embrace; and together “x” and “o” form a kiss on a face. Then there were auditory
associations such as the similarity in the pronunciation of “x” and “kiss.” But it very quickly became apparent that x most likely evolved from the written tradition. A simple, easily drawn shape, it entered the Western alphabet as the ancient Phoenician letter samekh for the consonant sound “s.” In early Hebrew it was the letter taw and makes an appearance in the Book of Ezekiel as a mark set “upon the foreheads” to distinguish the good men of Jerusalem from the bad.

When Christianity came along, it co-opted the “x.” “In Christian texts, one abbreviation of the Greek word Christos—meaning messiah—used the first two Greek letters of Christos, chi (X) and rho (P), combined into one shape,” says Stephen Goranson, a historian of religion at Duke University who studies the etymology of symbols and words. “So both orientations of crossed lines—X shape and the more-or-less lower case T shape—took on religious significance among Christians.” No one knows exactly how this happened: One story is that in 312 CE the Roman Emperor Constantine saw the chi-rho in a dream in which God told him “in this sign you will conquer.” Constantine went on to legalize Christianity, which later became the official religion of Rome.

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