David Laibson: Question About The Art of Self Management

I particularly resonated with your discussion of creating plans to perform tasks that you are likely to procrastinate. Adding intentionality to performing tasks through an outside accountability source makes people more likely to follow through with their plans. What are the deeper psychological mechanisms that make people more likely to finish work on time or perform laborious tasks if they hold themselves accountable to an outside source even if the source will almost certainly never follow up later? I mean this in the context of both human accountability partners (think: telling a friend you plan to go to the gym later) and inanimate accountability devices (think: Apple or Google Calendars).