Is it an invasion of privacy to film an animal in its burrow? Or a whale as it exhibits its penis in a courtship display? Or to use a remote camera to film a bear giving birth in its den? According to a film studies lecturer from the University of East Anglia, it could be. If an animal retreats to its burrow, it obviously doesn't want to be seen, he claims. Unlike the inhabitants of the Big Brother house, these creatures have not given consent. These assertions are a step further along the line from a cautionary ethical approach towards taking care not to disrupt wild behaviour. Instead, Brett Mills appears to be claiming that human emotions can be assumed within animals as well.

It was not the first time this week that recognisable human emotions have been assumed within animal species. A video accompanying a report in the journal Current Biology was released that seemed to demonstrate incontrovertibly a group of chimpanzees exhibiting grief. Anyone who has seen the video would have to have a hard heart not to have been moved. It showed the chimps apparently mourning the death of Pansy, an elderly member of the troop. The chimps gathered around her, moving her bedding gently and checking her breathing. Last year an equally striking image showed chimpanzees gathering to watch as the body of Dorothy, a group matriarch, was carried off. The chimps stood silently, their arms around each other's shoulders.

Both images have received widespread media coverage, most of it sympathetic to the idea that animals, especially primates, share human emotions such as grief, sadness, and even empathy. ITN news framed its report with the claim that "dignity in death may be just as important to chimpanzees as it is to humans". Much of the coverage referred to the growing body of "evidence" for this. The reports mentioned Professor Marc Bekoff's claim to have witnessed a magpie "funeral", where a group of magpies brought pieces of grass to the body of one of their members killed by a bike, and the accounts of how elephants often gather around a dead or dying animal.

I welcome the interest in this subject. For many years I have wanted to see an end to claims of human superiority based on the belief that animals, even if they feel, do not have the "higher" emotions of humans based on the capacity for symbolisation and self-awareness. This attitude derives from Judeo-Christian assumptions of human superiority, where it is believed that God created the universe and all life within it for man. It is man's use of language and symbolisation ("The Word was God") that marks humanity out from the animals, beliefs that have justified dominance, exploitation and abuse of animals. The increasing interest in animal emotions seems like an important first step in changing consciousness about our relationship with other species. But this does not necessarily mean that we should resign our critical faculties or fail to interrogate flaws in how the evidence is presented.

The popular media have taken the chimp pictures as "scientific" proof of animal emotions. Yet the interpretation lacks substantial data to back it up.

Dr Stuart Semple is a reader in evolutionary anthropology at Roehampton University who has been involved in the study of animal behaviour. He is concerned about the dangers of presenting speculation as science. To him, the grieving chimps video is "a classic case of anthropomorphism, the projection of human feelings on to animals, which is made easier because of their physiological resemblance to humans". Looking at the Daily Mail coverage, it's hard not to see his point. In one photo, a chimp with a rather ambiguous expression is shown sitting holding a banana. The caption reads: "Chippy the chimp looks downcast while clutching a banana in an enclosure." It doesn't take a semiotician to point out that we'd see something totally different if the caption was changed to: "Candy sits in his enclosure clutching his stolen banana."

Anthropomorphism is, of course, a term of insult and one of the key ways in which the human species has been able to disregard the abuse we have inflicted on animals. In the past, those who have shouted anthropomorphism most loudly have been those who have disregarded animal welfare issues and have promoted a resolutely "human-centred" version of the universe. Nevertheless, Semple is right to suggest caution. The real issue, he thinks, is less a dispute about the existence of animal emotions, and more a matter of establishing what exactly it is animals might be feeling. "I don't have a problem," he says, "with the idea that we share emotions. It's very likely that we do, since we share the same neurocircuitry. But it's a matter of investigating what emotions they might have and how they might feel, not about making assumptions of direct equivalence with humans."

Semple points to recent research that measured stress and social responses in baboons who had lost close relatives. Bereaved baboons showed an increase in stress hormones and in levels of social grooming: very similar responses to humans. "This kind of evidence is more compelling," says Semple. "It's rigorous and scientific. It allows us to speculate on what they are feeling or not."

Nowhere is this assumption of direct human equivalence writ more large than in the article by Mills about invading the privacy of animals by wildlife filmmaking. He writes: "Many species could be read as desiring not to be seen; animals in burrows and nests have constructed a living space which equates with the human concept of the home, and commonly do this in locations which are, by their very nature, explicitly hidden, often for practical purposes."

"Often for practical purposes" would seem to be the important part of this comment. Is the creature in the burrow hiding for reasons of "privacy" understood in human terms? Or is the burrow a practical response to self-protection? Without a rigorous study of the whole social behaviour and life cycle of the creature of the kind advocated by Semple, any interpretation is likely to be just speculation.

Why is this distinction between speculative observation and more rigorous study important? It's not because it would allow us to turn our back on animal welfare issues. Being cautious about conflating animal and human emotions doesn't mean assuming the absence of emotions. Professor Marion Dawkins, regarded as the world's leading advocate of the scientific approach to animal emotions, nevertheless advocates pragmatism. In the absence of certainty about what animal emotions are, we should behave towards animals as if they do share emotions.

The main reason this distinction is important is in case we go to the opposite extreme. If we assume animals have identical emotions to humans, perhaps we will insist on treating them as human. But until we know what animals really feel and what those feelings are, then treating them as identical to humans might be just as cruel as ignoring their feelings. If we take Mills' argument to its logical conclusion, would it mean that we should observe the privacy of a burrowing animal and never film it? What if that study revealed the animal's dependency on a species of plant or the need for conditions that were threatened elsewhere? If we failed to study, to film and to observe, we might lose that creature altogether. All of which suggests that investigating what exactly animals are feeling is one of the most pressing areas of contemporary research.