TRENTON, N.J. - A few generations after families move to the U.S. from Latin American countries, fluency in Spanish dies out and English becomes the dominant language, according to a new paper published by sociology professors from New Jersey and California.

The paper counters popular arguments that the size of Latino immigration to the U.S. could create a bilingual society and a fundamental change in American culture.

Such sentiments have played a role in debates over U.S. immigration law and touched off a controversy earlier this year over a Spanish-language version of "The Star-Spangled Banner."

The paper - authored by Douglas Massey at Princeton University and Ruben Rumbaut and Frank Bean at the University of California, Irvine - found Spanish giving way to English among Southern California's heavily Hispanic population.

The study suggests that Mexican immigrants arriving in Southern California today can expect only five out of every 100 of their great-grandchildren to speak fluent Spanish.

"Even in the nation's largest Spanish-speaking enclave, within a border region that historically belonged to Mexico, Spanish appears to be well on the way to a natural death by the third generation of U.S. residence," the researchers said in the paper, published in the September issue of the journal "Population and Development Review."

The authors of the new paper use survey data to show that Hispanics with each successive generation are becoming English speakers, just like previous immigration waves in U.S. history.

The paper draws on two studies, one conducted in 2004 and the other in 2001 to 2003, to assemble a sample of 5,703 Southern California residents. Among the group, 1,642 had Mexican roots and a total of 2,262 had Latin American ancestry.

Survival of Spanish among the descendants of Mexican and Central-American immigrants was higher than among other groups, but still followed the usual pattern of English taking over as the years passed.

Among Mexican-Americans with two U.S.-born parents but three or more foreign-born grandparents, only 17 percent spoke fluent Spanish. Among those with only one or two foreign-born grandparents, Spanish fluency dropped to 7 percent.

Only 5 percent of Mexican-Americans with U.S.-born parents and U.S.-born grandparents spoke Spanish fluently.

Among the third generation of Mexican-Americans, 96 percent prefer to speak English in their homes.

"Historical and contemporary evidence indicates that English has never been seriously threatened as the dominant language of the United States," wrote the authors of the paper. "What is endangered instead is the survival of the non-English languages that immigrants bring with them to the United States."