  $\textit{Embedded agents}$ are not explicitly separated from their
environment, lacking clear I/O channels. Such agents can reason about and
modify their internal parts, which they are incentivized to shortcut or
$\textit{wirehead}$ in order to achieve the maximal reward. In this paper, we
provide a taxonomy of ways by which wireheading can occur, followed by a
definition of wirehead-vulnerable agents. Starting from the fully dualistic
universal agent AIXI, we introduce a spectrum of partially embedded agents and
identify wireheading opportunities that such agents can exploit, experimentally
demonstrating the results with the GRL simulation platform AIXIjs. We
contextualize wireheading in the broader class of all misalignment problems -
where the goals of the agent conflict with the goals of the human designer -
and conjecture that the only other possible type of misalignment is
specification gaming. Motivated by this taxonomy, we define wirehead-vulnerable
agents as embedded agents that choose to behave differently from fully
dualistic agents lacking access to their internal parts.
