The American criminal justice system is based on the
notion that individuals are responsible for their actions and can be punished
when they choose to violate societal standards. Thus it is said to be rooted in
the concept of “free will.” If all human actions and choices are caused by factors
beyond the actor’s control, and is therefore morally excused, then that action
or choice should not be legally punishable. This leads to the absurd conclusion
that no actions or choices should be legally punishable.
Criminal liability follows from a determination that an
actor engaged in criminal conduct by inquiring (1) did the defendant
voluntarily engage in proscribed conduct (actus
reus), and (2) if he did, was he aware of the circumstances that made his
conduct criminal (mens rea)? Actus
reus and mens rea include the
presumption that individuals are responsible agents capable of making choices
and intending the natural consequence of their acts. “Voluntarily” implies that
an individual exercised his free will in doing the act, or that he could have
done otherwise.
It is helpful in discussing the relationship between
criminal law and behavioral genetics to distinguish between the broad concept
of free will (“theoretical free will”) and “legal free will.” Theoretical free includes philosophical,
metaphysical, psychiatric, and biological perspectives on the subject. Legal
free will is simply based on the presumption that individuals actively choose
to engage in criminal conduct. Legal free will
theory contends that human behavior in a given situation is the result of
individual choices made by autonomous actors.
It assumes that individuals have the inherent ability to choose or
choose not to act in a certain way.
Human choice is fundamental to the operation of the system of laws, a
necessary presumption to foster better social relationships. This is based on the belief that social
systems are strengthened by holding people responsible for their conduct. Legal free will is value preference; it
exists along with causal agents.
Our criminal justice system is an “excusing system.” In addition to the requirement of a certain
mental state (mens rea) such an
intent, purpose, knowledge, recklessness, or negligence, our system recognizes
certain excuses from criminal liability. The generally recognized excuses are
mistake, accident, provocation, insanity, and duress. An excuse says that even though I did the
act, I am not culpable because some disability in my freedom to choose the
right thing makes it inappropriate to punish me.
Excuses focus on the actor and his subjective mental
state. Excuses are different from
justifications used to avoid criminal responsibility, such as
self-defense. Justifications entitle
others to act in the same way under similar circumstances. Excuses do not make an act any less
wrongful, and therefore do not create an entitlement to act in a certain
way. The question raised by determinism
is whether predispositions to engage in behavior that society has declared
criminal resulting from genetic or other biological factors should serve as an
excuse to criminal liability.
Because full determinism and application of the causal
theory of excuse lead to the absurd result of no responsibility, the concept of
“degree determinism” is used to allow acceptance of determinism as well as
criminal responsibility. Degree
determinism holds that all human conduct is not fully caused; that varying
degrees of determinism and free will exist in all actions on a continuum from
freedom to causation. Thus the question
becomes at what point on the continuum does human behavior become so determined
that the actor lacks choice and thus his actions are not blameworthy?
The one biologically based defense recognized as a
defense to criminal responsibility is insanity. The defense is limited, however, to medical
proof that a defendant suffered from a mental illness or defect. Courts reject claims of mental illness based
on a genetic predisposition, generally on the basis that the defendant can
appreciate the wrongfulness of his act notwithstanding any genetic
predisposition.
Defendants have offered a variety of defenses based on
biological deficiencies, including genetic deficiency, automatism, amnesia, Post-traumatic
Stress Syndrome, premenstrual syndrome, along with severe environmental
deprivation and battered woman’s syndrome, and recently “affluenza,” the
defense that a teenage defendant was unable to understand the consequences of
his actions because of his financial privilege. Defendants have argued that
their acts were not voluntary, in that because of a genetic predisposition to
addiction, violence, impulsivity, or other biological trait they did not
exercise free will, but were compelled to act. These attempts have been generally
unsuccessful. Courts seek a causal link
between an asserted behavioral predisposition and the criminal act, and they
are unwilling to accept statistical data when considering whether that link
exists for a specific act.
Defendants generally have used behavioral predisposition
arguments in the sentencing phase rather than in the guilt phase of a trial,
arguing that their genetic makeup or socio-economic background is a mitigating
factor in their culpability. This is a
double-edged sword, however, for courts can use the behavioral disposition as
an aggravating, as opposed to mitigating, factor in sentencing.
