new line of mice with a special accessory: an upgraded memory and learning system. When these new

new line of mice with a special accessory: an upgraded memory and learning system. When these new and improved mice ran through an IQ test, they outperformed normal mice. Tsien pulled off an extraordinary engineering trick, creating a lineage of smarter mice. This is cowboy science, showing the power of genetic tampering to open the door to evolutionary changes. In a world of competition, one would imagine that selection should favor these smart mice who have better recall of essential foraging routes, previous social interactions, and places to rest out of harm’s way from predators. But in biology, there are always trade-offs. Benefits in one area of life are often accompanied by costs in others. Several months after Tsien’s report, a follow-up study of the same memory-enhanced mice appeared in print, also in a distinguished scientific journal. But this time there was no media fanfare. The new work was carried out by Min Zhuo at Washington University, an ex-member of Tsien’s lab and a co- author of the original paper. Zhuo’s new paper confirmed that memory-enhanced mice were indeed smarter, but also showed that they were more sensitive to pain, licking their wounds more and for longer periods of time than normal mice. Though it is unclear whether Zhuo’s results reveal heightened pain sensitivity, stronger memories for pain, or some combination of these and other processes, what is clear is that the engineering that led to smarter mice led to much more. Tsien and Zhuo’s work shows that even with targeted, artificial changes in the underlying biology, unanticipated consequences are common. It also shows that deep within the biology of every organism lies hidden capacities and potential for change. Unleashing these sub rosa capacities can have both beneficial and costly consequences for the individual and group. The idea I develop in this chapter is that our capacity for evil evolved as an incidental, but natural consequence of our uniquely engineered brain. Unlike any other species, our brain promiscuously combines and recombines thoughts and emotions to create a virtually limitless range of solutions to an ever-changing environment. This new form of intelligence enabled us to solve many problems, but two are of particular interest given their adaptive consequences: killing competitors and punishing cheaters in a diversity of contexts. But like the painful fall-out from artificially engineering a smarter mouse, so too was there fall-out from the natura/ engineering of a smarter human: a species that experiences pleasure from harming others. This is part of the recipe for evil. This chapter sets out the evidence to support the idea that evil evolved as an incidental consequence of our brain’s design. I begin by discussing the two general processes that landed us in the unforeseen and uninhabited niche of evildoers: the evolution of byproducts and promiscuous connections within the human brain. Because these are general processes, we will take a short reprieve from matters specifically evil. Hauser Chapter 1. Nature’s secrets 21 HOUSE_OVERSIGHT_012767