"That's not fair!" is children's battle cry.

• Position: YOUR LIFE - Brief article

Most parents of multiple children have, at some point, heard their offspring utter the phrase, "That's not fair," in response to punishment or preferential treatment for a sibling. While parents have their own views on when it is fair to treat siblings differently, research from the University of Missouri, Columbia, shows that a parent's feelings of fairness matter little compared to a youngster's when developing a good parent-child relationship.

"Children themselves are different," says Amanda Kowal, assistant professor of human development and family studies. "They can be different ages and genders and have varying interests, needs, and behaviors. These dissimilarities make differential treatment appropriate on some occasions. When parents treat children differently, the parent-child relationship quality appears to be much more affected by the child's perception of whether the treatment was fair rather than the parent's opinion.

"Understanding parents'...