"Quid is 6 months old and just seemed to be settling into our family of three people, two older dogs and a cat. But all at once, she is more sensitive," writes Alexandra Horowitz, a cognitive scientist who studies dogs. Why? "Quid has entered teendom: thought to be, for dogs, from approximately 6 months old (varying by breed) through their second birthday." We ignore this phase to our detriment, Alexandra says. "As is widely acknowledged in humans, adolescence is a distinct stage of development." 📷 @danielterna #nytopinion