the function of PANIC/GRIEF is to motivate animals, including primates, to come into contact with others. Others of their species could certainly help aid their survival, even if the one who was lost was unable to reunite with their caregiver.
O’Connor applies Panksepp’s PANIC/GRIEF framework directly to human bereavement, arguing that the system’s evolutionary function is social re-engagement mediated by opioid reward upon contact.
, The grieving brain the surprising science of how we learn, 2022thesis