Dogs typically focus on the most remarkable aspect of each situation, such as threatening stimuli in a frightening situation. Recognising and interpreting threats quickly is important for survival. Dogs under the influence of oxytocin were more interested in smiling faces than they were in angry ones.

It seems that the hormone oxytocin influences what the dog sees and how it experiences the thing it sees,” says doctoral student Sanni Somppi. Researchers in the Canine Mind group showed 43 dogs images of smiling and angry faces on a computer screen. Each dog was tested twice: once under the influence of oxytocin, which was administered as part of the test, and once without oxytocin. The dog’s gaze on the images and pupil size were measured with an eye-tracking device. Emotions and attentiveness guide the gaze and regulate pupil size, making eye tracking a window into the dogs’ minds.

https://go2pedia..com.ng/2017/11/smiling-human-faces-are-attractive-to.html

Dogs have common sense pass some human

The poster above me is right though, and I must add, many dogs are more loyal than many humans