[Sandra Mafnas]

Sandra Mafnas asked the Naked Scientists:
   
Can dogs sense that a person is bad?  If so what in the "bad" human triggers a dog to react or protect their owners?

Love the show!  

Thank you

Sandra Mafnas
Surprise, Arizona

What do you think?

[grizelda]

I've read that dogs in say, Thailand, will give short shrift to tourists who've just come from Vietnam, where they eat dogs, so I guess their olfactory organization of the world is pretty sophisticated.

[imatfaal]

Dogs can definitely react to the non-verbal cues of their owner - perhaps they can also sense factors that we don't notice in strangers as well.  What one has to bear in mind is that any situation like this we can see patterns that don't really exist because we want our pet to be special and not just bonded to us by provision of food and water!

[yor_on]

A dog is very much a extension of what you feel. Most dogs make up a pack, hopefully they see you as a leader, so although wary of new people and circumstances they are going to look at you for their reactions. If you get duped and the person has dog knowledge the dog will get fooled too, as long as the other guy isn't afraid. Dogs have a acute olfactory sense and will react on fear, as that produce a chemical reaction. They might also attack, or if you like protect you, from people that behave differently from the 'dog human norm' as small children that don't act 'dog human normal'. But if you get a baby, or have kids, they will learn as they grow up with them. They are very much the same as us but you need to set the limits, and you can not trust the dog to differ between a 'bad human'  and someone that is afraid or act differently, like being handicapped.

[RD]

Dogs can definitely react to the non-verbal cues of their owner

olfactory too ... http://news.bbc.co.uk/1/hi/health/3682722.stm

[CliffordK]

Dogs are very sensitive to a number of cues, both with the owner, and with the stranger.

Good vs Bad is very complex.

However, they should be able to sense things like fear, kindness, authority, anger, etc.

I.E.  If you are kind to dogs, then they will know.  If you are mean to dogs, they will know.

[vernahll2]

We don't fully understand the senses that animals have. But yes dogs do react to different people differently. They can also sense when someone is friendly towards them and when someone is not.

[Bored chemist]

Plainly the answer is no.
http://www.timesonline.co.uk/tol/news/uk/article5683650.ece