Children as young as 3 are likely to say that things made by humans have owners, but that natural objects, such as pine cones and sea shells, are not owned, according to a new study published by the American Psychological Association.

"Determining whether an unfamiliar object is owned is very important because it shows us that young can decide when they're allowed to take or handle something," said the study's lead author, psychologist Karen Neary, PhD, of Waterloo University in Canada. "This article provides the first evidence about how children judge the ownership of things based on whether those things are 'artificial' or 'natural.'"

A total of 131 children, ages 3 to 6 and mostly from white, middle-class families, were tested in five different experiments at their daycare or preschool. The findings are published online in the APA journal .

In the first experiment, 3-year-olds looked at pictures of five recognizable human-made objects (fork, teddy bear, ball, shoe, truck) and five familiar natural objects (leaf, shell, rock, branch, pine cone). The testers did not name the objects but asked each child, "Does this belong to anyone?" Children named the human-made objects as owned 89 percent of the time and natural objects as owned 28 percent of the time.

To ensure that the children weren't basing their judgments on personal experiences, such as owning a teddy bear, the researchers showed six photos of unfamiliar objects to a different group of 57 children, ages 3 to 5. Half of the objects appeared to have been made by people and the other half looked natural. They asked the children the same question: "Does this belong to anyone?" They also conducted a similar experiment with a separate group of 3- and 4-year-olds, but this time the testers told the children which objects were human-made or natural.

In one "unfamiliar objects" experiment, children of each age mostly viewed the natural objects as not being owned, but children younger than 6 were less consistent when asked if the synthetic objects belonged to anyone. However, in the second experiment, the 3- and 4-year-olds judged the human-made objects to be owned more often. This was because the children were told that they were human-made objects, the researchers said.

In a final experiment, the researchers questioned whether 4- and 5-year-olds based their of ownership on the desirability of objects. They showed them a picture of a woman named "Sally" and two pictures of unfamiliar objects, one natural and the other human-made, and asked half the children, "Which one belongs to Sally?" Seventy-two percent of these children said the human-made object belonged to Sally. When they asked the other children which object Sally liked better, 47 percent said Sally liked the human-made object better.

"Although children thought Sally would like the natural objects just as much, they were still more likely to say that she owned the human-made objects," said study co-author Ori Friedman, PhD, also of the University of Waterloo. "It appears children's views of object ownership are not based on whether they think the object is more likeable."

It was difficult to judge if the children consistently considered the objects' origins in determining whether they were owned, according to the researchers. Nonetheless, when the children learned which objects were artificial or natural, they were more likely to say unfamiliar artificial objects were owned.

"It's possible are more likely to think artificial objects are owned and natural ones are not because of their experience with objects," Friedman said. "For example, if the is made of plastic, like a toy, then they assume it most likely belongs to someone. They may transfer that assumption to all things made of plastic."

They also might reason that artificial objects are likely to be owned because they are made by people and natural objects are unlikely to be owned because they are not, according to the researchers.

"The current studies show that young children have differing expectations about the ownership of all kinds of objects, both familiar and unfamiliar, which is contrary to previous research that suggests children view natural objects as similar to artificial ones," Neary said.

More information: "Artifacts and Natural Kinds: Children's Judgments About Whether Objects Are Owned," Karen R. Neary, PhD, Julia W. Van de Vondervoort and Ori Friedman, PhD, University of Waterloo; Developmental Psychology, online.