The heads and hearts of atheists may not be on precisely the same page. That’s the implication of recently published research from Finland, which finds avowed non-believers become emotionally aroused when daring God to do terrible things.

“The results imply that atheists’ attitudes toward God are ambivalent, in that their explicit beliefs conflict with their affective response,” concludes a research team led by University of Helsinki psychologist Marjaana Lindeman. Its study is published in the International Journal for the Psychology of Religion.

Lindeman and her colleagues describe two small-scale experiments. The first featured 17 Finns, recruited online, who expressed high levels of belief, or disbelief, in God. They read out loud a series of statements while skin conductance data was collected via electrodes placed on two of their fingers.

Some of the statements were direct dares to a deity (“I dare God to make my parents drown”). Others were similarly disturbing, but did not reference God (“It’s OK to kick a puppy in the face”). Still others were bland and neutral (“I hope it’s not raining today”).

The arousal levels of the believers and non-believers followed precisely the same pattern: Higher for both the God dares and otherwise unpleasant statements, and lower for the neutral ones.

Compared to the atheists, the believers reported feeling more uncomfortable reciting the God dares. But skin conductance data revealed the underlying emotional reactions of the two groups were essentially the same. This suggests that taunting God made the atheists more upset than they were letting on (even to themselves).

Of course, perhaps it wasn’t the presence of God, but rather the subject matter of the statements (such as the death of their parents) that caused the atheists’ emotional arousal. The second experiment was designed to test that hypothesis. It featured 19 Finnish atheists, who participated in an expanded version of the first experiment. It included 10 additional statements—variations on the God dares which excluded any mention of supernatural forces. For example, in addition to “I dare God to turn all my friends against me,” they read out loud the statement: “I wish all of my friends would turn against me.”

The results: The atheists showed greater emotional arousal when reading the God-related statements than while reading the otherwise nearly identical sentences that omitted the almighty. To the researchers, this indicates that “even atheists have difficulty daring God to harm themselves and their loved ones.”

“There are at least four potential explanations for these findings,” Lindeman and her colleagues write. The simplest and most provocative is that “atheists’ explicit beliefs may differ from the implicit reactions that exist outside of conscious awareness.”

But other possibilities are equally plausible. Atheists “may have found using the word God stressful because others, possibly their friends and family, do take God seriously,” they note. Alternatively, they may have found the idea of God “absurd or aversive,” leading to the heightened emotional response.

Finally, the researchers note, “although atheists did not currently believe in God, they may have been influenced by their own previous beliefs.” They point to research from 2006 that found three-quarters of American atheists were once believers.

Perhaps the emotional response measured in this study is an echo of that previous belief. If so, it suggests that even for committed non-believers, it’s difficult to totally erase the idea of God from one’s psyche.