Since the discoveries of Darwin, evidence has gradually mounted refuting the notion that the natural world is the product of a deity or other outside designer. Yet this idea remains firmly lodged in the human brain.

Just how firmly is the subject of newly published research, which finds even self-proclaimed atheists instinctively think of natural phenomena as being purposefully created.

The findings ''suggest that there is a deeply rooted natural tendency to view nature as designed,'' writes a research team led by Elisa Järnefelt of Newman University. They also provide evidence that, in the researchers’ words, ''religious non-belief is cognitively effortful.''

In the journal Cognition, Järnefelt and her colleagues describe three studies conducted at Boston University, the first of which featured 352 North American adults recruited online. All were shown a series of 120 photographs, including natural landscapes and human-made artifacts.

They were instructed to assess whether ''any being purposefully made the thing in the picture'' by pressing keys designated ''yes'' or ''no.'' Approximately half of the participants did so under the ''speed condition,'' in which they had no more than 865 milliseconds to respond to each photo.

Not surprisingly, the researchers found that ''religious participants’ baseline tendency to endorse nature as purposefully created was higher'' than that of their non-religious counterparts. More importantly, however, they found that non-religious participants ''increasingly defaulted to understanding natural phenomena as purposefully made'' when ''they did not have time to censor their thinking.''

The results suggest that ''the tendency to construe both living and non-living nature as intentionally made derives from automatic cognitive processes, not just practiced explicit beliefs.''

The second study used the same procedure as the first, but the participants were 148 North American adults ''who were recruited via the e-mail lists of atheist and other explicitly non-religious associations and organizations.''

The results mirrored those of the first study, in that atheists ''increased their tendency to endorse nature as purposefully made by some non-human being when judging natural entities under speeded conditions.''

A third study of non-religious people from Finland, a country where atheism ''is not an issue, and where theistic cultural discourse is not present in the way it is in the U.S.,'' produced similar results.

''Design-based intuitions run deep,'' the researchers conclude, ''persisting even in those with no explicit religious commitment and, indeed, even among those with an active aversion to them.''

So ''true non-belief may be even rarer among adults than previously suggested," as Järnefelt and her colleagues put it. This, they argue, helps explain why so many people misunderstand the theory of evolution.

We tend to absorb ''newly learned scientific information'' into our existing belief systems, the researchers note. In this case, such an attempted synthesis leads to the mistaken notion that natural selection is ''a quasi-intentional designing force that gives animals the functional traits that they need in order to survive.''

So members of the new atheism movement shouldn’t get too cocky that their ideas will eventually prevail. And science educators trying to instill the basics of evolutionary theory will have to find a way to do so while acknowledging their students' instinctive tendency to make the leap from creation to creator.

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