As an evolutionary psychologist, Jeon Joonghwan studies about why people believe that disgusting behavior is wrong. Jeon graduated from the Department of Biology at Seoul National University (SNU), earned a master's in behavioral ecology at SNU, and earned his doctorate in evolutionary psychology at the University of Texas at Austin. He currently serves as an associate professor at the Kyunghee University Humanitas College (International Campus). His books include The Old Tool Box and Human Nature Is the Answer.