When dog-parents spend extra time scratching their dogs’ bellies, take their dogs out for long walks and games of fetch, or even when they feel constant frustration over their dogs’ naughty chewing habits, they are gradually shaping their dogs’ personalities. Dogs, like people, have moods and personality traits that shape how they react in certain situations. New findings from Michigan State University went where few researchers have gone before to reveal that, also like humans, dogs’ personalities likely change over time.