Nonhuman, All Too Human: Toward Developing Policies for Ethical Chimera Research

In this chapter, we address the ethical challenges raised by chimera research policy, using as a case study the National Institutes of Health (NIH) 2016 proposal to change its policy governing the funding of human–nonhuman animal chimera research. In this case, we find a troubling shift from a focus on nonhuman animal welfare to poorly thought-out concerns with humanization. Despite the restrictions on modifying early-stage nonhuman primates, the proposed changes make it possible to modify animals in ways that may significantly impact neurological functions and behavioral capacities with serious implications for the welfare of research subjects. The NIH’s restrictions target the development of humanized brains—particularly in nonhuman primates—reflecting, we suspect, a concern to avoid creating chimeras that are in some sense “too human.” While we endorse robust restrictions on chimera research, particularly in the face of a growing globalization of research in varied and inconsistent regulatory environments, we maintain that policies should not be based on beliefs about inherent human uniqueness but should (minimally) instead conform to the widely accepted 3Rs framework for research involving nonhuman animals, and our best welfare science.