Four things we need to know about extreme self-sacrifice

Abstract A comprehensive explanation of extreme self-sacrifice would ideally clarify not only the proximate mechanisms leading to this behaviour, but also its developmental origins, its functions (if any), and its history. The theoretical framework set out in my target article has something to say about all of these dimensions, and many of the criticisms raised in the commentaries can therefore be addressed under those four main headings. In my response, I also discuss a set of proposals for further extending the framework. Finally, I conclude by distilling from the discussion a host of novel questions requiring further investigation.