Because he likes to
is how we make connections with other people.
There are diff levels of eye contact, & also the babies proper level of eye focus is about the distance from mom's elbow 2 mom's face. We all want to love & be loved, & eye contact is one way for us to do that before we speak. If you are looking at the eyes you can't help then to look at the face, & a focus of nonverbal communication.