Joy, fear, surprise, disgust, sadness. These are the basic emotions dogs feel that are also easy enough for humans to identify. But what about more complex emotions?

Many dog owners are convinced their dogs feel guilty when they're caught misbehaving. In the same way, many owners are sure their dogs feel pride at having a new toy or bone. But it gets tricky when you assign these sorts of emotions to a dog. These are definitely emotions felt by humans, but are they also felt by dogs?

PHOTOS YOU'LL LOVE: How does a dog see the world?

Why we question the presence of complex emotions is wrapped up in the way we get to those emotions. The American Psychological Association explains, "Embarrassment is what's known as a self-conscious emotion. While basic emotions such as anger, surprise or fear tend to happen automatically, without much cognitive processing, the self-conscious emotions, including shame, guilt and pride, are more complex. They require self-reflection and self-evaluation."

Essentially we're comparing our behavior or situation to a social expectation. For instance, guilt comes when we reflect on the fact that we've violated a social rule. We need to be aware of the rule and what it means to break it. So, can dogs feel guilt? Well, exactly how self-reflective and self-evaluative are dogs?

Among humans, children begin to experience empathy and what are called secondary emotions when they are around 2 years old. Researchers estimate that the mental ability of a dog is roughly equal to that of an 18-month-old human. “This conclusion holds for most mental abilities as well as emotions,” says Stanley Coren in an article in Modern Dog Magazine. “Thus, we can look to the human research to see what we might expect of our dogs. Just like a two-year-old child, our dogs clearly have emotions, but many fewer kinds of emotions than found in adult humans."

In other words, if 18-month-old children can't yet experience these emotions, and dogs are roughly equal to them in cognitive and emotional ability, then dogs can't feel these self-reflective emotions either. At least, that's what researchers have concluded so far.

Is that guilt or fear?

This little puppy might feel guilty for chewing on clothes, or could just be worried about getting in trouble. The two aren't the same emotion. This little puppy might feel guilty for chewing on clothes, or he could just be worried about getting in trouble. The two aren't the same emotion. (Photo: InBetweentheBlinks/Shutterstock)

The evidence for primary emotions like love and happiness in dogs abounds, but empirical evidence for secondary emotions like jealousy and guilt is sparse. And this is partially because it's difficult to create tests that provide clear-cut answers. When it comes to guilt, does a dog act guilty because she knows she did something wrong, or because she's expecting a scolding? The same expression can come across as guilt or fear. How do we know which it is?

Scientific American explains it further:

"In wolves, it is thought that guilt-related behaviors serve to reinforce social bonds, as in primates, by reducing conflict and eliciting tolerance from other members of the social group. The same could be true of dogs, though their social groups would primarily include humans. The problem is that the display of the associated behaviors of guilt are not, themselves, evidence of the capacity to emotionally experience guilt... It may still be some time before we can know for certain whether dogs can experience guilt, or whether people can determine if a dog has violated a rule prior to finding concrete evidence of it."

Guilt, and other secondary emotions, are complicated. That's exactly why cognitive awareness and emotional capacity in dogs is still a topic under study. In fact, it's an area that has grown significantly in recent years. We may discover that dogs have a more complex range of emotions than we're aware of today.

Dogs are highly social animals, and social animals are required to navigate a range of emotions in themselves and those around them to maintain social bonds. It wasn’t so long ago that scientists thought that dogs (and other non-human animals) didn’t have any feelings at all. Perhaps our understanding of dog emotions is simply limited by the types of tests we've devised to understand their emotions. After all, we're trying to detect a sophisticated emotional state in a species that doesn’t speak the same language.

There's a lot we don't know

Dogs experience many emotions, but researchers are still trying to figure out exactly which. Dogs experience a range of emotions, but researchers are still trying to figure out exactly what those emotions are. (Photo: Hysteria/Shutterstock)

Marc Bekhoff makes the argument for leaving the possibility open. In an article in Psychology Today he writes, “[B]ecause it's been claimed that other mammals with whom dogs share the same neural bases for emotions do experience guilt, pride, and shame and other complex emotions, there's no reason why dogs cannot.”

Keeping the possibility open is more than just an emotional animal rights issue. There is a scientific basis for continuing the research. A recent study showed that the brains of dogs and humans function in a more similar way than we previously thought.

Scientific American reports that "dog brains have voice-sensitive regions and that these neurological areas resemble those of humans. Sharing similar locations in both species, they process voices and emotions of other individuals similarly. Both groups respond with greater neural activity when they listen to voices reflecting positive emotions such as laughing than to negative sounds that include crying or whining. Dogs and people, however, respond more strongly to the sounds made by their own species."

Until recently, we had no idea of the the similar ways human and dog brains process social information.

So do dogs feel shame, guilt and pride? Maybe. Possibly. It's still controversial, but for now, there seems to be no harm in assuming they do unless proven otherwise.

Jaymi Heimbuch ( @jaymiheimbuch ) focuses on wildlife conservation and animal news from her home base in San Francisco.