In a scary new study published in the the journal Animal Cognition, researchers discovered that bomb-sniffing dogs are susceptible to the prejudices of their handlers.
The researchers recruited 18 dogs certified by law enforcement agencies. As a test site, they used four rooms in a drug-and-explosive-free church. The researchers left the first room untouched. In the second, they taped up a sheet of red paper. In the third, they hid a few Slim Jims as a decoy. And in the fourth, they taped red paper to a stash of Slim Jims.
The dog handlers were told they might encounter the scent of pot or gunpowder up to three times per room, sometimes marked with red paper. It was a flat-out lie—there were no target scents. But the dog teams still called 225 false alerts—most often at the site of the red paper, whether there were Slim Jims there or not.
