The finding shows short-term memory in babies works similarly to that in adults, who routinely break information into chunks to remember more of it.
The discovery indicates that this memory-boosting trick does not seem to be learned, but may be an innate human ability.
Adults break down phone numbers and social security numbers into smaller chunks, like 443-297-9960, to more easily remember them.
Researchers have wondered whether this was a technique we pick up over time, or if it is fundamentally built into our memory system.
So psychologists Lisa Feigenson and Justin Halberda of Johns Hopkins University in Baltimore tested babies to see how their memories work.
They found that 14-month-old children could more easily recollect hidden toys and remember greater numbers of toys, if the objects were sorted into groups.
"Our work offers evidence of memory expansion based on conceptual knowledge in untrained, preverbal subjects," said Lisa Feigenson, assistant professor of psychological and brain sciences in the university's Krieger School of Arts and Sciences, who worked on the study with colleague Justin Halberda.
"What we have basically done is show that very young children, who can usually only keep track of about three objects at once, can keep track of more if they use the kind of conceptual, linguistic, perceptual and spatial cues adults also use," she added.
The study is published in the July 14 issue of the Proceedings of the National Academy of Sciences.
In the team's experiment, the 14-month-olds were shown four toys which were then hidden in a box.
The children then were allowed to search for the missing toys. Sometimes, two of the four toys were secretly withheld in another place.
The researchers observed how long the youngsters continued to search the box, the idea being that they would search longer if they remembered there were more toys yet to be found.
The researchers found the children would search longer when the four toys consisted of two groups of two familiar objects, cats and cars, and one of each type had been withheld.
That indicated that the youngsters were using mental chunking as a way to recall more items at a time.
The team also found that 14-month-olds can use spatial grouping cues (the researchers grouped six identical orange balls in three groups of two before hiding them) to expand memory, in the same way that adults group digits when remembering phone numbers.
When provided with such cues, the little ones could remember up to six objects.
These results suggest that memory is not merely a passive storage system that makes a "carbon copy" of our experiences.
Instead, Feigenson says, the results show that from at least early toddlerhood onward, memory is constantly being restructured and reorganized to maximize its efficiency.