Weird Science
Sorry, cat people, dogs are smarter
There’s a new twist to the perennial argument about which are smarter, cats or dogs.
It has to do with the number of neurons in their cerebral cortex: the little grey cells associated with thinking, planning and complex behaviour — all considered hallmarks of intelligence.
The first study to count the number of cortical neurons in the brains of a number of carnivores, including cats and dogs, has found that dogs possess significantly more of them than cats.
The study found dogs have about 530 million cortical neurons while cats have about 250 million, compared with 16 billion in the human brain.
The researchers analysed the brains of one or two specimens from eight carnivore species: ferret, mongoose, raccoon, cat, dog, hyena, lion and brown bear.
They expected that their measurements would confirm the intuitive hypothesis that the brains of carnivores should have more cortical neurons than the herbivores they prey upon.
That was because hunting is more demanding, cognitively speaking, compared with the herbivore’s primary strategy of finding safety in sheer numbers. However, that proved not to be the case. The researchers determined that the ratio of neurons to brain size in small- and medium- sized carnivores was about the same as that of herbivores, suggesting that there is just as much evolutionary pressure on the herbivores to develop the brain power to escape from predators as there is on carnivores to catch them.
For the largest carnivores the neuronto- brain- size ratio was actually lower.
They found that the brain of a golden retriever has more neurons than a hyena, lion or brown bear, even though the bigger predators have brains up to three times as large.
“Our findings mean to me that dogs have the biological capability of doing much more complex and flexible things with their lives than cats can,” says study leader Suzana Herculano- Houzel, an associate professor of psychology and biological sciences at Vanderbilt University in the United States.
Media- savvy makes you more sceptical
The more you know about the media and how it works, it appears, the less likely you are to believe conspiracy theories — even ones you might find politically tempting.
US researchers surveyed nearly 400 participants online in 2016 to gauge how their media literacy — a combination of media knowledge and psychological traits connected with processing news messages — might relate to their endorsement of conspiracy theories.
The researchers found that “individuals who give credence to conspiracy theories know comparatively little about how the media work”.
They also found that the greater a person’s knowledge about the media — from the kinds of news covered, to the commercial context in which news is produced, to the effects on public opinion news can have — the less likely a person will fall prey to conspiracy theories.
Study leader Stephanie Craft, a journalism professor at the University of Illinois, said this applied even where conspiracy theories resonated with an individual’s political beliefs.
The study asked the American participants about the strength of their belief in any of 10 conspiracy theories, split evenly between those associated with liberal and conservative perspectives.
It also asked separate questions to determine participants’ ideological beliefs.
The researchers found that liberals with higher news media literacy were less likely to believe any or all of the five liberal conspiracy theories — among them that the US government knew about the 9/ 11 terrorist attacks beforehand. and that there’s a link between childhood vaccines and autism.
Likewise, conservatives with higher news media literacy were less likely to believe five conspiracy theories commonly associated with conservatives — among them that Barack Obama was not born in the US and that global warming is a hoax.