BEIJING, Aug. 2 (Xinhuanet) -- Learning 10 new words a day is no big deal for a toddler, a new study suggests.

Children go through a "vocabulary explosion" at about 18 months of age that involves learning new words at a rate that often amazes their parents. Researchers have previously thought complex mechanisms must govern this voracious rate of word-learning.

"The field of developmental psychology and language development has always assumed that something happens at that point to account for this word spurt: kids discover things have names, they switch to using more efficient mechanisms and they use their first words to help discover new ones," said study author Bob McMurray of the University of Iowa. "Many such mechanisms have been proposed."

But these mechanisms aren't necessary, according to McMurray, whose study of a mathematical model to describe the vocabulary explosion is detailed in the Aug. 3 issue of the journal Science.

McMurray says that while children may engage those types of specialized mechanisms to help them learn new words, computational simulations he conducted suggest that simpler mechanisms ¢w such as word repetition and learning multiple words at once ¢w can explain the vocabulary explosion.

"Children are going to get that word spurt guaranteed, mathematically, as long as a couple of conditions hold," McMurray said. "They have to be learning more than one word at a time, and they must be learning a greater number of difficult or moderate words than easy words. Using computer simulations and mathematical analysis, I found that if these two conditions are true, you always get a vocabulary explosion.

"Clearly, the specialized mechanisms aren't necessary," McMurray added. "Our general abilities can take us a lot farther than we thought."

(Agencies)