The Illusive "Reasonable Person": Can Neuroscience Help the Mentally Disabled?

[L]aws and institutions must go hand in hand with the progress of the human mind. As that becomes more developed, more enlightened, as new discoveries are made, new truths disclosed, and manners and opinions change with the change of circumstances, institutions must advance also, and keep pace with the times. We might as well require a man to wear still the coat which fitted him when a boy, as civilized society to remain ever under the regimen of their barbarous ancestors. --Thomas Jefferson (1) INTRODUCTION Recent discoveries and progressions in neuroscience have indicated that mental illnesses and disabilities are largely, if not completely, determined by biological or otherwise physical processes. Despite these findings, the law has been slow to embrace this progress. For centuries the specifics of mental illness have remained unknown, and perhaps the distinction between mental and physical disabilities has remained defensible over time. Quite simply, the legal system has lacked adequate tools to grapple with this issue; as put by the late astronomer Carl Sagan, we have been "bamboozled" (2) by the proper conceptualization of mental illness. The reasonable person standard finds its roots in a time when mental disability was described by terms such as "distracted" or "lunatick," (3) over two hundred years before Thomas Jefferson acknowledged the need for legal progress. (4) Current negligence doctrine denies any exception from the "reasonable person" standard for the mentally disabled. It has long been accepted, however, that those with physical disabilities should not be held to such a standard. Today, new discoveries have been made, and we are enlightened as to the nature of mental disability. (5) Technological and diagnostic advancement in recent years has granted new insight into consciousness and the workings of the human brain. While our full grasp of these concepts has not yet been realized, it can hardly be denied that perception of mental disabilities has changed drastically in a relatively short period. (6) Neuroscience gives us the ability to question the bases of a mental disability and continues to prove that we have the capability to objectively identify the presence of mental disability. As such, neuroimaging has shown a substantial link between physical processes and cognitive functioning and necessarily calls into doubt the current physical-mental dichotomy in our tort jurisprudence. New knowledge in the arena of neuroimaging may finally provide us with the ability to make such determinations a reality in the courtroom. It is not surprising that the law has lagged behind our other social institutions in this regard, but the fact that emerging technologies have been embraced in numerous fields already (7) suggests it is only a matter of time until the legal profession follows suit. (8) In the tort law context relevant to this Note, the "neuroscience revolution" (9) in particular has been recognized as a possible "catalyst for significant changes." (10) The realm of negligence is fertile ground for significant change, and a relatively simple solution to the disparity between treatment of the mentally disabled vis-a-vis those with physical infirmities is right under our feet. This Note argues that the distinction between what constitutes a physical versus a mental disability can no longer rationally be sustained. Specifically, its purpose is to show that providing an exception to the "reasonable person" (11) standard in negligence actions for the physically disabled (12) while withholding it for those with mental infirmities (13) is increasingly indefensible. Part I briefly tracks the origins of the current rule in tort law that holds the mentally and physically disabled to separate standards. This discussion is purposely left short because of the breadth of scholarship tracing the standard. (14) Part II seeks to justify, through neuroscientific brain imaging evidence, the claim that numerous disabilities are fundamentally the same regardless of their label as either mental or physical. …