Jessica Peterson/Getty ImagesI used to notice it with my dog Jaws: Whenever I would walk in the door brooding after a bad day, he would seem... off somehow. I guess you could classify it as clingier. More restless. I wasn't sure if it was just my imagination or maybe there was something more to his behavior.As it turns out, it probably wasn't all in my head.A growing body of research points to the surprisingly sophisticated ways dogs pick up on …