The twelve short paragraphs printed near the comics are a specific journalistic invention. Their form follows from newspaper economics rather than from the astrological tradition they draw on.
Traditional practice required individual data
Astrological consultation historically involved calculating a chart for a person's exact birth date, time and place. The positions of many bodies and their angular relationships were the working material.
That process was slow and required skill, so it served individuals who could pay for it. Nothing about it scaled to a mass audience.
A newspaper cannot ask millions of readers for their birth time. Something reducible to a single fact was required.
Sun sign alone made mass distribution possible
Almost everyone knows their birthday, and the birthday alone determines the sun sign. That makes the entry point universal and requires no calculation by the reader.
Twelve categories then divide the readership into groups a writer can address in a fixed number of lines. The layout requirement and the number of signs fit conveniently.
Practitioners of the older tradition have often regarded sun-sign writing as a drastic simplification. It uses one element of a chart that traditionally involved many.
The column format imposes its own rules
Each entry must occupy roughly equal space regardless of what is being said. Uniform length is a typesetting constraint that shapes the writing.
Entries are written well ahead of publication to meet production schedules. Nothing can refer to events between writing and printing.
Language is therefore general enough to apply broadly, addressing work, relationships, money and mood. Specificity would fail for most readers on most days.
Readers supply the specificity themselves
A statement that fits many situations invites each reader to attach their own circumstances to it. The reader completes the text.
Psychologists have long described the tendency to accept general personality descriptions as personally accurate. The effect is well documented and does not depend on belief in astrology.
This is not necessarily deception. Many readers describe the column as a prompt for reflection rather than a prediction they expect to verify.
The column occupies a distinctive place in American papers
Horoscopes sit alongside comics, puzzles and advice columns in the section readers turn to for daily habit rather than news. Their function is closer to a routine than to reporting.
Papers have periodically debated whether to carry them, sometimes adding disclaimers describing the feature as entertainment. Reader attachment has generally kept them in place.
Digital delivery has extended the format rather than replacing it. Apps and social feeds still divide readers into twelve groups and address each in a paragraph.