Maria Legerstee, professor of psychology at York University revealed that babies as young as three months feel jealous when their mom's attention is not directed at them exclusively. Babies aged three, six, and nine months were involved in the study and a researcher distracted
their mother as a part of the study.
"Babies did not like that at all," she said. "No matter what the age, they got very upset and did all kind of things to get our attention. They kicked their legs, yelled out loud, and turned in their seats. I've never seen anything like it."
The study is a part of a series that are looking at socio-cognitive development in babies.