Professor Admits Citation Omissions

A Harvard psychologist and his former student formally admitted this month to publishing improperly cited research in the scientific journal Nature.

Starch Research Professor of Psychology Jerome Kagan and Conor Liston ’02 said in a correction published in Nature’s Feb. 6 issue that they failed to credit other researchers’ scholarship in an article the two co-authored for the journal last October.

The correction came after several well-known developmental psychologists lodged complaints with the journal.

Kagan and Liston said in the correction that their article, which detailed the results of a study on long-term memory in infants, was misleading because it implied it was the first major study on the topic.

In fact, they said, a large body of previous scholarship—especially work by Patricia J. Bauer of the University of Minnesota—does exist and influenced their study.

“Our brief list implied that this study was the first to demonstrate the emergence of long-term memory for events in infants. On the contrary, a large body of work published by P. Bauer, among many others, addresses this issue exactly and also forms the basis of the methodology developed for our study,” the correction reads.

But Kagan and Liston also wrote in the correction that “more extensive citation of work in this area was not possible” because of restrictions by Nature on citing research in brief articles.

Assistant Professor of Psychology Jesse Spedeker said the pair made the right decision in submitting a correction.

“Professor Kagan is well-respected. No one is going to think less of him for acknowledging the oversight,” Snedeker said. “I hope that this will remind reviewers and editors of Nature that they also have an obligation to ensure that the proper work is cited.”

In the article, entitled “Brain Development: Memory Enhancement in Early Childhood,” Liston and Kagan suggested that memory improvement during infancy is directly related to the development of the brain’s frontal lobe and hippocampus—the parts of the brain responsible for memory retention and retrieval.

In the study that led to their conclusion, Liston and Kagan ran experiments on three age groups—nine-, 17- and 24-month-old children—that tested the child’s ability to mimic new but easily imitated actions like placing a towel in a trash can or wheeling a toy truck across the floor.

Four months later, researchers asked the same subjects to repeat the tasks on verbal cue, but this time without a visual demonstration.

According to the results of the study, 11 percent of the youngest age group successfully repeated at least one of the multi-step tasks they performed as nine-month-old babies. One hundred percent of the oldest children were able to repeat the same tasks without a demonstration after the four-month interval.

Liston and Kagan said in the correction that the study is significant because it provides empirical data linking memory improvement with a specific year of development.

And despite problems with citing previous research, they added that their experiment was still innovative because it was the first to space the testing sessions four months apart.

—Staff Writer Kimberly A. Kicenuik can be reached at kicenuik@fas.harvard.edu.