What determines the "default behaviour" if no self-control is applied?
Most documents refer to satisfaction of immediate desire, but that does not seem to explain how quite sophisticated behaviors can occur as the result of a failure of self-control. A temptation to eat fast food which involves purchasing it, or to consume internet pornography, can require higher or executive functions to satisfy in terms of computer operation and engagement with a purchasing process. A temptation to take illegal drugs can potentially require delaying gratification for an unknown period of time (to find a supplier).
So is there research on what determines the behavior without self-control, and how it is able to "hijack" executive functions that should rightfully be limiting the undesirable behavior?