“This fascination is a consequence of inadequate experience with fire during development,” evolutionary biologist Daniel Fessler told Live Science. In his own research, Fessler has discovered at least 19 societies that expose children to fire at the tender age of three; most other cultures introduce children to fire between the ages of five and eight. Only in western countries are the flames taboo throughout childhood, and this helps spark a child’s curiosity. What makes fire so hot and smoky? How can it be contained? This curiosity lasts for roughly a three year period, studies suggest—a lethal amount of time to be literally playing with fire. One result of this curiosity is that U.S. children under the age of five are twice as likely to die in home fires than the rest of the population. Meanwhile, curious kids start nearly 50,000 fires in the U.S. each year, according to the National Fire Protection Association—nearly half are kindled by children under the age of six. Each year, the American Red Cross estimates that the carnage costs the United States $280 million in property damage and results in 300 deaths. “The motives that drive fire learning are only incompletely satisfied, with the result that, throughout life, fire retains greater allure or fascination than would normally be the case,” Fessler says. In response to these concerns, several western countries have begun exposing small children to fire. In Berlin, educators now conduct week-long fire workshops for 5 and 6-year-olds, the Washington Post reports. But not all experts are convinced. For instance Paul Schwartzman, a mental health counselor who’s worked with the U.S. fire protection association for 20 years, argues that such programs could give kids a false sense of confidence around fire. “They don’t have the intellectual ability to understand what’s going to happen or how quickly it can get out of control,” Schwartzman warns. But Frieder Kircher, a deputy assistant chief with the Berlin Fire Department, agrees with Fessler suspects the real danger is keeping kids in the dark about fire. “All the things you prohibit are interesting for young children,” he says. “The more you prohibit them, the more interesting they are.”