Toronto: Even three-year-olds can sense that while man-made objects are owned, natural products like pine cones and sea shells are beyond ownership, new research has found. “This provides the first evidence about how children judge the ownership of things based on whether those things are artificial or natural,” said psychologist Karen Neary of Ontario's University of Waterloo.

“Determining whether an unfamiliar object is owned is very important because it shows us that young children can decide when they're allowed to take or handle something,” added Neary, who led the study.

A total of 131 children, aged three to six years and mostly from middle-class families, were tested in five experiments at their day care or preschool, the journal Developmental Psychology reports.

In the final experiment, researchers questioned whether four and five-year-olds based their judgments of ownership on the desirability of objects, according to a Waterloo statement.

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 them said the man-made object belonged to Sally. When they asked the other children who 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 man-made objects,” said study co-author Ori Friedman, also from Waterloo.