Dogs really are man's best friend, new research has confirmed once again. A study has found that dogs are able to tell the difference between humans' happiness, anger, fear and sadness from facial expressions alone. Scientists found that seeing a smiling human activates a unique region of a dog’s brain that does not respond to negative facial expressions. Meanwhile, negative emotions are processed differently across the entire brain – revealing that a dog's world is far more complex than 'good' and 'bad'. #dogs #pets