I have also heard that dogs can tell by scent whether they are family or not: for instance, my dog ADORES my husband's dad. She does not act that way when anyone else comes over. And I was mortified the first day I ever took her to my in-law's house, the pup jumped through the open car window and ran into the house like she owned it (ahead of me). She seems to know 'pack' from 'non-pack.' I think they can tell, but like you said I think they can also discriminate.

This is indeed a funny idea. I ran into this myself when I was at work and my Mom came to my house. She had never met my dogs before

My dogs who are normally pretty reserved with strangers gushed over her. Misty who is my most stranger shy dog crawled on her lap and greeted her like she was an old friend.

Since dogs have senses we don't have and are a heck of a lot more intuitive, I believe it's not necessarily a chemical discernment but something deeper than that; perhaps a discernment of a bond and connection that family members have. Maybe they "see" us in another family member. They know there's a connection unlike any other connection.

So more on the lines of a spiritual/connection discernment. I believe they're open to sensing those things, a lot more than we are, especially with a particularly sensitive dog.

there probably is something to that sandy. i can be relaxed and happy around friends, but family is family, and there's a bond there that only comes from being family....the dogs probably can sense that as well. it always has impressed me though that my family gets more respect and friendliness....i think it's great.

i was talking to my mom last night about this, and she thought part of the reason teagan was good with her when she restrained her was that my mom looked at teagan and asked her to stay with her, told her she needed her. and my mom meant it. i don't know, but teagan is a very intelligent and perceptive dog (not that i'm biased, but she obviously uses her brains in ways luc, while of course also a smart dog, does not - personality differences i think) and i can also see teagan responding well to be asked (vs. being told) and i can see teagan being able to preceive the difference. though again, i may be anthropomorphic there, but i do think teagan can tell between the two. of course, regardless, she also allowed my family to tell her what to do throughout christmas, so they got special treatment even when they didn't appeal to her better nature.

You may have something with the intuition and the way you act around your family. Dogs can read human body language better than we can. Perhaps that...along with their super noses. Hepper 1986 was mentioned previously. The following article is also a good read (for a science communication).

http://www.fbi.gov/hq/lab/fsc/backissu/july2004/research/2004_03_research03.htm

I would think a dog would be able to tell the difference in somebodies scent if they became afraid, angry, or calm. I would think pheromones would change as we change emotions and the dog would have the ability to differenciate those changes through smell. I watched a documentary that talked about dogs being able to tell the differnce of at least 17 different components in explosives. I would think they would be able to smell the changes in our chemical composition as well. Don't know about matching though. I haven't heard or seen anything on that either myself.

I definately think dogs can smell family. My sister came to visit and had never met my then 2 year old Boxer. I was driving back from a horse show the same day her plane landed. I told her, on the off chance she got there first I would leave the door open.

I made good time home so I FULLY expected to be the first to the farm. When we were walking to the house my boxer stoped and then got SUPER SUPER excited. I then saw a purse by the door and then my sister immerged from my house.

You think the dog would think what is a stranger doing in my house. Granted Boxers are friendly but Ava was off the charts happy to see Lynda. My sister LOVES Ava to this day for the royal first greeting she received.