When it comes to counting, a remote Amazonian tribespeople have been found to be lost for words. Researchers discovered the Piraha tribe of Brazil, with a population of 200, have no words beyond one, two and many.
The word for "one" can also mean "a few", while "two" can also be used to refer to "not many".
Peter Gordon of Columbia University in New York said their skill levels were similar to those of pre-linguistic infants, monkeys, birds and rodents.
He reported in the journal Science that he set the tribe simple numerical matching challenges, and they clearly understood what was asked of them, told BBC.
Their lack of enumeration skills is just one of the mental and cultural traits that has led scientists who have visited the 300 members of the tribe to describe the Piraha as "something from Mars."
Daniel Everett, an American linguistic anthropologist, has been studying and living with Piraha for 27 years.
Besides living a numberless life, he reports in a separate study prepared for publication, the Piraha are the only people known to have no distinct words for colours, reports The Globe and Mail.
Gordon arranged for the tribespeople to take part in some number matching tests.
"Piraha participants were actually trying very hard to get the answers correct, and they clearly understood the tasks."
While Piraha adults had difficulty learning larger numbers, Piraha children did not.
"One can safely rule out that the Piraha are mentally retarded. Their hunting, spatial, categorisation and linguistic skills are remarkable and they show no clinical signs of retardation," Gordon said.
They also show some other unexpected differences from many world cultures.
"Not only do the Piraha not count, but they also do not draw," Gordon said. "Producing simple straight lines was accomplished only with great effort and concentration, accompanied by heavy sighs and groans", told Reuters.