Tag Archives: Harley S. Smyth

When You Hear Hoofbeats Look for Horses Not Zebras

Hilton Read? Theodore E. Woodward? Ele and Walt Dulaney? Harley S. Smyth? Anonymous?

Dear Quote Investigator: In medicine the symptoms of a patient are often compatible with a variety of ailments. A skilled diagnostician will use probabilistic reasoning when deciding which ailment is the most likely. Bayesian inference first highlights common maladies instead of rare ones. Here are three versions of a germane saying:

  • When you hear hoofbeats look for horses not zebras.
  • If you hear hoof beats in the distance don’t expect a zebra.
  • When you hear hooves think of horses before zebras.

Admittedly, these adages work best outside of a zoo and on a non-African continent. Would you please examine the provenance of this saying?

Quote Investigator: The earliest published evidence located by QI appeared in the “Arkansas Gazette” of Little Rock, Arkansas in October 1962. Emphasis added to excerpts by QI: 1

The father of a young man who was there reports that at the University of Arkansas School of Medicine this week a doctor surrounded himself with about a dozen students and sought to go to the heart of proper diagnostic procedure.

In the end he summed up good diagnosis this way: “When you hear hoofbeats in the night, look for horses — not zebras.”

The passage above occurred in a column called “Our Town” by Charles Allbright, but the participants were unidentified.

An earlier origin for the saying has been suggested. However, the claim is weakened by a multi-decade delay. For example, a variant statement has been ascribed to Dr. Theodore E. Woodward circa 1940s. Evidentiary support appeared in the 1980s. See the citations further below.

This article presents a snapshot of current knowledge, and future researchers may discover material that alters the ascription.

Here are additional selected citations.

Continue reading

Notes:

  1. 1962 October 5, Arkansas Gazette, Section: Sports and Markets, Our Town by Charles Allbright, At First, Anyway, Quote Page 1B, Column 1, Little Rock, Arkansas. (GenealogyBank)