Humans are not the only creatures to feel grief or jealousy or stick to fair play.
Man's best friend is more closely aligned to humans than many dog owners may realise.
On the eve of his trip to New Zealand, US animal behaviour expert Marc Bekoff, Professor Emeritus of Ecology and Evolutionary Biology at the University of Colorado, has revealed some of the canine moral code, including a complex range of emotions and the inner workings of the "wolf pack" at play time.
"Our sense of compassion, of empathy, of co-operation, of justice didn't just arise with us. There's definitely non-human animal roots," he said. "They may, for example, grieve differently but that doesn't mean they're not grieving."
Bekoff will be a keynote speaker at the NZ Companion Animal Council conference in Rotorua next week.
A key part of his work has been studying dogs' play behaviour, which revealed the code by which they abide.
"If they ask someone to play with them, they're obligated to obey the rules of the game," he said, noting he had observed the importance of the "play bow", for which dogs crouch on their forelimbs and raise their backsides.
"The play bow is a very basic signal which says, 'come play with me'. If it gets out of control and one dog bites the other, they might look at them to say, 'What are you doing? I thought we were playing.' Then they'll do a play bow. They can't verbalise it, so they use actions to prevent misinterpretations of, say, a very hard bite."
Bekoff said if dogs and other animals didn't abide by the rules they were booted from the group.
"It's like kids in the school yard."
Bekoff has published 26 books on animal emotions, behaviour and intelligence and more than 1000 essays. In his research he has observed his own dogs' behaviour when one of the group died.
"Some would mope around, they'd stop playing, they'd stop eating, they're obviously upset. Others don't seem as upset as the other animals. I would say the grief or the joy that a dog feels is as important and as deep as it is to a human."
Dogs care and chat, says Dan
Few people spend more time with dogs than canine behaviourist "Doggy Dan" Abdelnoor.
Muriwai's Abdelnoor is amazed by the emotions of his dogs Inca, Moses and Peanut. "It's absolutely fascinating to see what they're communicating and their depth of emotion," he said.
"Peanut is a matriarch: she's 10, big, confident and a very loving, caring dog. She's incredibly skilled at reading other dogs.
"A large black American bulldog came running down the beach to say hello.
"However, its tail was right under, meaning it was a little bit unsure and quite timid."
Inca and Moses asserted their dominance but Peanut " walked over and put her head underneath its head and nudged the bulldog's head into the air. She basically said to this dog, 'Come on, chin up'.
"And immediately the bulldog leapt into action, its tail came up and it started running around, because it knew it was accepted.
"She could have just walked right past that dog but she actually chose to help another dog that was struggling with its confidence."Matthew Theunissen