Human Brain Stuck in the Stone Age, Says U of G Prof

June 05, 2009 - News Release

Why in a modern world do more people believe in ESP, ghosts and angels than in scientific theories such as evolution? A University of Guelph psychology professor tackles this question and others in a new book, Caveman Logic: The Persistence of Primitive Thinking in a Modern World.

“We're trying to get by in our modern world using a Stone-Age mind,” said Hank Davis, a specialist in evolutionary psychology.

He says his book is the product of more than two decades of pondering, teaching and writing about "the powerful influence of irrational, delusional thinking that is anchored to our Pleistocene-era brain circuitry." Davis laments that much of this primitive thinking is supported by modern social institutions.

Although science offers rational explanations for natural phenomena, all too often people embrace irrational fantasies — the same kind that probably provided comfort to our prehistoric ancestors, Davis said.

“It’s astonishing when you think about the many ways our behaviour is still controlled by the clueless caveman who lives inside us."

He offers many examples drawn from newspaper headlines and mundane events in daily life. In 2004, a woman claimed to see the face of the Virgin Mary staring up at her from a half-eaten grilled cheese sandwich. The incident sparked a bidding war on the Internet.

A poll in 2007 found that nearly 70 per cent of Americans believe angels and demons are active forces in the world, while a 2009 survey concluded that only 39 per cent believe in Darwin's theory of evolution.

Even non-religious people often thank God or “the heavens” in response to good news, said Davis. “Our language is riddled with expressions like that. It’s funny, but it also reflects the kind of superstitious beliefs I’m talking about.”

He notes that people consult their horoscopes “just for fun” or, when faced with a personal crisis such as a marriage breakup or the death of a loved one, trot out the old cliché: “Everything happens for a reason.”

“Of course, there are causes and effects in the natural world, but that’s usually not what people have in mind,” said Davis. “They say: ‘Everything happens for a reason’ because on some level they believe these events are part of a higher plan that will have an impact on their future.”

Although many of the examples he cites are humorous, Davis argues the condition itself is no laughing matter. He notes that delusional thinking can quickly cascade into more dangerous actions. "In many ways, we’re wallowing in ignorance and quick to defend our delusions and tribal loyalties — often to the death — when they are challenged.”

He believes such “caveman logic” is problematic even in those who profess to keep such beliefs to themselves. "The bottom line is that so-called 'private' beliefs rarely stay private. It’s more likely that someone who believes in fairies, for example, will want to share those beliefs with others, or vote for a candidate who talks about fairies. They may even push to have those beliefs taught in public schools."

Despite its strong hold on the human mind, our predisposition toward irrational thinking and behaviour can still be overcome, said Davis. He concludes that “biology is not destiny. It’s clear that we are predisposed to do some very bad and stupid things. But we can resist those impulses. For example, we diet. We all love those yummy, fatty cheeseburgers, but we can still avoid them. Every one of us has aggressive impulses and sexual impulses, but most of us can resist those as well.”

Getting people to question their impulses and primitive beliefs is going to take work, he says. “But it's absolutely necessary to do so if we want to move forward. If I didn't believe change was possible, I never would have written Caveman Logic.”

Contact: Prof. Hank Davis, Department of Psychology, University of Guelph, 519-824-4120, Ext. 53504 or

For media questions, contact Communications and Public Affairs: Lori Bona Hunt, Ext. 53338 or, or Barry Gunn, Ext. 56982,

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