Focus on Research
Penn State Intercom......October 25, 2001

Early struggles in vocabulary
development can hamper
economically disadvantaged children

By Paul Blaum
Public Information

When socioeconomically deprived children fall behind in spoken vocabulary development during their first three years of life, they are very likely to have lifelong struggles in all their studies in school. RESEARCH_Farkas

Even current early intervention programs such as Head Start may not be enough to close this learning gap, a University researcher said.

"Those children in our society who grow up in poverty or near poverty are adversely affected by their mother's own vocabulary deficit during their earliest years when they are learning to speak at home," according to George Farkas, professor of sociology. "Social class differences in vocabulary growth emerge at the very earliest ages among both black and white Americans, and they attain a substantial magnitude by 36 months of age.

"These social class differences widen during the fourth and fifth years of life, although this occurs more strongly among African-Americans than among whites. Half of the social class differences in vocabulary growth rates can be traced to the differences in family linguistic instruction provided by mothers of varying social classes."

By the time children reach age 6 and the first grade, they are learning to read, and from that point their vocabulary development, regardless of class or race, proceeds roughly at the same pace. Unfortunately for disadvantaged children, their earlier deficiencies in vocabulary learning will continue to have long-term repercussions in their teen-age years, especially in the areas of vocabulary, reading and mathematics.

In adult years, the consequences are often low-skill and poorly paid jobs that pe rpetuate the cycle of poverty, according to Farkas, a faculty associate with the Population Research Institute. Kurt Beron of the School of Social Sciences collaborated on the research.

Between 1986 and 1996, data were collected from several thousand children between the ages of 3 and 14, including the Peabody Picture Vocabulary Test, comprised of 175 increasingly difficult words. The tester read the word to the child, who then pointed to one of the 4 pictures that best described its meaning. When the child failed to identify six out of eight consecutive items, the test ended, and the child was assigned a score or "ceiling."

"By analyzing these data according to the child's month of age, beginning at 36 months, we were able to examine the trajectory of oral vocabulary growth by social class in unprecedented detail," Farkas noted.

The researchers also compared the child's progress in vocabulary development with the mother's skills and habits of vocabulary and speech.

"It is not enough that the mother herself have a good vocabulary," the researcher said. "It is also necessary for mothers to teach letters to their babies, talk out loud to them and read books to them regularly and consistently."

Paul Blaum can be reached at


College degree not
a guarantee of success

By Paul Blaum
Public Information

Without realistic career goals and planning, a college degree may not lead to automatic job success or satisfaction, a University educator said.

"In the 1960s, a university degree by itself was a virtual guarantee of access to professional and managerial employment," said Kenneth C. Gray, professor of vocational education. "Unfortunately, for today's generation of young people, this is no long-er true, because now there are more four-year college graduates than there is commensurate employment. Ironically, a number of good-paying, prestigious jobs are still available that do not require a college degree but which continue to go begging."

Gray notes that many high schoolers, even those who dislike formal studies, opt for college because they don't know what else to do with their lives.

According to the U.S. Bureau of Labor Statistics, out of 2.8 million high school graduates in 1997, 67 percent were enrolled. But, while college enrollments have reached unprecedented levels, so have college dropout rates, not to mention the number of remedial classes needed to keep marginal students in the classroom.

"The sad fact is that only 25 percent of college students graduate on time, get through school without the need for remedial courses and find employment that matches the level and type of education pursued," said Gray, author of "Getting Real: Helping Teens Find Their Future," published by Corwin Press.

Two out of three college students withdraw at least once before they finish school, and more than one-half will need six years to graduate. Out of all arts and humanities graduates, only one third will find employment in line with their academic experience. For all graduates, regardless of major, the figure is one-half.

"Teens have two choices. They can let fate and labor market Darwinism decide their future, or they can be proactive and plan for success," Gray pointed out.

Parents should encourage teen-agers to look long and hard at their prospects, size up reality and plan their post-high school lives accordingly. High school students, especially those less confident or focused, have to be taught to balance hopes and aspirations with talents and opportunities, Gray said. Teens have to ask themselves where they want to go in terms of a career, and then ask themselves if college is the best vehicle to take them there as opposed to a technical school and apprenticeship program or even the military.  

Paul Blaum can be reached at

Marine methane consumed
by consortia of bacteria

Methane-consuming archaeobacteria and sulfate-reducing bacteria, acting together, are responsible for consuming most of the methane in the world's oceans, according to a team of microbiologists and geoscientists.

"Past research had shown that there is a consortia of these two very different single-celled organisms, and indirect tests indicated they might be the source of methane consumption," said Christopher H. House, assistant professor of geosciences. "We decided to directly test if these organisms are responsible."

Research team members Victoria J. Orphan, graduate student, and Edward F. Delong, chair of the science department at Monterey Bay Aquarium Research Institute, were responsible for identifying the organisms in the consortia.

House and Orphan, working with Kevin D. McKeegan, professor of Earth and space sciences, University of California, Los Angeles, employed an ion probe that uses cesium ions focused to a very small spot to slowly erode the cells for study. The probe allowed samples of the carbon from the consortia to be tested, beginning with the outer cells and then tunneling toward the middle of the clump.

Carbon isotopes were the component of interest because the percentages of different carbon isotopes found in living tissue relates directly to what the organism eats. If a bacteria eats food depleted in carbon 13, then the bacteria will be depleted in carbon 13. Methane is very depleted in carbon 13 so a carbon signature low in carbon 13 would indicate the bacteria ate methane.

To confirm their findings, Kai-Uwe Hinrichs, assistant scientist at Woods Hole Oceanographic Institute, tested the lipids in the bacteria and obtained a similar carbon isotope signature.

Marine methane is produced by archaeobacteria in the absence of oxygen, usually in the marine sediments. About 80 percent of this methane is consumed in the ocean and never enters the atmosphere.