Outlining the relationship between the English youth justice system and the developmental neurobiology of the human brain

The dominant idea of responsibility is that criminal responsibility is founded
on mental capacity – specifically, individual autonomy and practical ration-
ality.1 Voluntarist accounts argue that persons are criminally responsible
for their past criminal conduct if they rationally and freely choose to break
the law and disregard the opportunity to act otherwise than they did. The
choice to act and the capacity to reason are essential to criminal law doc-
trine and the idea of criminal responsibility.2 For example, where an adult
intended to kill or cause really serious harm and deliberately chose to act, it
would be fair to blame and punish for the offence of murder. A 10-year-old
child who commits the same offence and is substantially impaired on account
of their developmental immaturity is similarly considered to have still chosen
to break the law by killing another individual and can be convicted of mur-
der. This is because the minimum age of criminal responsibility (MACR) is
10 years, and no developmental immaturity-inspired defence is operating in
England and Wales. This chapter will consider the latest developments in
neuroscientific research, alongside the limitations of brain imaging data, and
assess whether current criminal justice responses to childhood offending in
English law are the most appropriate.