On Tuesday, Twitter ditched its "favorites" functionality, previously executed by clicking a gold star button beneath a tweet, for "likes" and a red heart icon. For the most part, this change hasn't gone over well.
Nevertheless, historically and semiotically, hearts and stars have more in common than you might think—for one thing, both symbols are universally understood to represent very specific objects (namely, the vital organ and the celestial body) that they don't actually resemble.
The act of "liking" a tweet raises two far-reaching cultural questions: How did the heart come to symbolize affection, and how did the heart ideogram (you know: ❤️) come to symbolize the physical heart?
Barbara G. Walker writes in The Woman's Dictionary of Symbols and Sacred Objects that Christianity conceived the heart as a "stand-in for the soul" long before we had any notion of the extent of the brain's power. In ancient Egypt, the ib was one of several vital parts of the human soul, drawn directly from the mother's heart. Udo Becker's The Element Encyclopedia of Symbols describes the heart's role in Egyptian religion as "the center of the powers of life, the will and the mind." The organ is also imbued with spiritual meaning in Judaism and Islam.
But until the 14th century, the symmetrical shape that any modern preschooler could readily identify as a heart was associated with leaves, and sometimes testicles, in heraldry.
It's possible that medieval scientists' less-than-precise anatomical understanding of the heart's structure inspired contemporary artists' renderings thereof (if you squint, the two halves kind of look like ventricles, or maybe atria?), and in turn, the shape that's familiar to us now. The bilateral curves of ♥ could also be a reference to the female body, specifically the buttocks or vulva.
The origins of the heart's ties to romance are also murky, but they may have their roots in sexuality. Not only has the heart been linked to genitals, but also to the silphium plant, once used as a primitive form of birth control. In Catholicism, the Sacred Heart symbol—which stands for love and devotion to God—dates back to at least the seventeenth century and the divine visions of Saint Margaret Mary Alacoque.
In modern times, the heart as a logograph for "love" was first cemented in the public consciousness by 1977's I ♥ NY tourism campaign.
Receiving a Twitter favorite always made me think fondly of elementary school, when a metallic star sticker on your graded homework signified approval from your teacher. Though the five-pointed star has emerged as the pictorial default, four-, six-, seven-, and eight-pointed varieties have appeared in various cultures.
"Of course, real stars do not have any points at all, of any number," Walker writes, "though one may imagine points from the twinkly effect imparted by the passage of their light through the Earth’s atmosphere."
Stars have been an object of fascination to cultures and religions around the world, throughout history. While the heart was widely considered the internal manifestation of the soul, according to many traditions, the stars are souls externalized: sometimes the souls of the dead, sometimes of the unborn, sometimes of heroes, sometimes of everyone on Earth. Becker describes stars, particularly the way they illuminate the night sky, as a "symbol of spiritual light piercing through the darkness," as well as an emblem of "high or all too high ideals."
In the same way that no single one of the dozens, hundreds, or thousands of tweets you've favorited was really your favorite, a ♥ is not a blood-pumping muscle and a ★ is not a high-density ball of plasma. But call them likes or favorites, both gestures serve as small windows into your (internet) soul.
Molly Fitzpatrick is senior editor of Fusion's Pop & Culture section. Her interests include movies about movies, TV shows about TV shows, and movies about TV shows, but not so much TV shows about movies.