Why might grown-ups harbor affection for a ratty old blanket or well-worn stuffed dog? Part of the reason is probably nostalgia, but there seems to be a deep emotional attachment to the objects as well. It’s called essentialism, or the idea that objects are more than just their physical properties.

Consider: If someone offered to replace a cherished stuffed toy animal, like your wedding ring, with an exact, indistinguishable replica, would you accept? Most people refuse, because they believe there is something special about their particular ring. It’s the same reason we might feel revulsion at wearing a shirt owned by a murderer. Objects are emotional.

Belief in essentialism starts early. In a 2007 study published in a journal, researchers told 3- to 6-year-old children that they could put their toys in a copy box that would exchange them for duplicates. The kids didn’t care whether they played with originals or duplicates of most plush toy animals, but when offered the chance to duplicate their most cherished item, 25 percent refused. Most of those who did agree to duplicate their beloved toy wanted the original back right away, the report said. The kids had an emotional connection to that blanket, or that teddy bear, not one that looked just like it.

Even in adulthood, those emotions don’t fade. In a study published in August 2010 in the Journal of Cognition and Culture, researchers asked people to cut up photographs of a cherished item. While the participants cut, the researchers recorded their galvanic skin response, a measure of tiny changes in sweat production on the skin. The more sweat, the more agitated the person.

The results showed that participants had a significant stress response to cutting up pictures of their beloved stuffed toys wholesale compared with cutting up a picture of a valuable or neutral item. People even became distressed when researchers had them cut up a picture of their cherished item that was blurred past recognition.