Humans can smell as well as dogs, rodents; ending century-old ‘myth’ proving contrary: Research

A US researcher has concluded that the human's sense of smell is as good as those of rats and dogs, debunking an almost 100-year myth which said the opposite.

According to a report in the journal Science, written by Rutgers University, neuroscientist John McGann said that down the ages writings made us believe that human smelling capability is inferior.

“For so long people failed to stop and question this claim, even people who study the sense of smell for a living,” he said. “The fact is that sense of smell is just as good in humans as in other mammals, like rodents and dogs.”

McGann said that been humans have been credited with identifying 10,000/- different smells, buyout the fact is that the figure is closer to 1 trillion.

Paul Broca, 19th century anthropologist and surgeon in his 1879 writings, wrote that the human’s olfactory area in the brain was smaller than the other larger parts, thus originating the myth of the inferior sense of sense of humans.

The differences between humans, dogs and rodents olfactory capabilities may only be restricted to sensitivities to different odours.
McGann argued that humans had free will and did not have to depend on smell to survive unlike dogs and other animals.

Even Sigmund Freud the father of psychoanalysis was influenced by Broca, and said that people’s lack of sense of smell made them more prone to mental illness.“It has been a long cultural belief that in order to be a reasonable or rational person, you could not be dominated by a sense of smell,” McGann said. “Smell was linked to earthly animalistic tendencies.”

McGann further said that the human olfactory bulb occupied just 0.01 per cent of the human brain as compared to 2 per cent in mice.
However, it’s absolute size is large, in adult humans, it can be up to 2 inches, having the same quantity of neurons as compared to those of other animals.

Since the olfactory capabilities of humans mice and rodents differ only in sensitivities to certain odours, “We are capable of tracking odour trails, and our behavioural and affective states are influenced by our sense of smell,” McGann wrote.

Although humans may be superior in smelling and differentiating between fine wines, dogs are still better that differentiating between the different types of dog urine at the nearest fire hydrant.