(FILES) This undated handout photo downloaded from the Symbio Wildlife Park's facebook page shows Pygmy marmosets at the Symbio Wildlife Park in Sydney. Naming others is considered a marker of highly advanced cognition in social animals, previously observed only in humans, bottlenose dolphins and African elephants. Marmoset monkeys have now joined this exclusive club, according to a new study published in Science on August 29, 2024. The diminutive primates use loud, high-pitched calls to assign each other "vocal labels," as shown in research conducted by a team at the Hebrew University of Jerusalem. (Photo by MICK MARIC / SYMBIO WILDLIFE PARK / AFP) / --RESTRICTED TO EDITORIAL USE- MANDATORY CREDIT "AFP PHOTO / SYMBIO WILDLIFE PARK" - NO MARKETING AND ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS- NO ARCHIEVE (Photo by MICK MARIC/SYMBIO WILDLIFE PARK/AFP via Getty Images)