You remember the bad ex gf because you don’t want repeatability of the trauma.

Without retention of the memory of trauma, you won’t be forming new experiences.

Amygdala creates emotional responses and utilizes long term memories.

We know from ape studies and amphibian studies that amygdala evolved differently in humans than with other animals.

That's interesting.. so you mean that human memory is not bugged and perfect from an evolutionary perspective?

Isn't it also arguable that retention of trauma is inherently bad from an evolutionary perspective? Let's say someone retains a traumatic event, gets depressed, ends up committing suicide. In that case, if the brain optimized for survival, it would be beneficial to erase the memory.

I'd argue that the probability of death occurring as a result of severe trauma is greater than the probability of death occurring as a result of forgetting an experience

Perhaps at this time in history, in some cultures. I doubt our hunter-gather ancestors got depressed and killed themselves after surviving a trauma. I don't think depression and PTSD and suicide happen at constant rates across human cultures, and certainly not in apes or other mammals. You're confusing social pressures and cultural effects with biological evolution.

I was just giving you an example of memories that would not be evolutionary beneficial to retain. Obviously that ex gf/suicide was an anecdote to our imperfect memory retention, and has nothing to do with evolution

Perhaps not, but the part of our brain responsible for optimizing contentment would ideally prefer deleting traumatic memories

I don't think any part of our brain is "responsible for optimizing contentment" or "deleting traumatic memories."

In evolutionary terms, individual organisms are optimized for reproducing and living long enough to give their offspring (more accurately, their genes) a good shot at survival. Richard Dawkins explains that in The Selfish Gene and other books. "Contentment," a human social construct, and classifying a memory as "traumatic" probably have little to do with what evolution has optimized us (or any organism) for. If we reproduce and pass on our genes, then slowly die a miserable and traumatic death, that makes no difference in terms of evolution.

ok. so your mind is made up. thanks for sharing.

I do think human memory is finely tuned and aligned with our evolutionary journey.

Retention of traumatic memory is actually an evolutionary edge we have..if you don’t retain that memory, we will keep repeating the same fatal mistake again and again.

I would even go further and look into studies re amygdala and how it works with people who have substance abuse or addiction issues.

Suicidal tendencies have to do with brain chemical imbalances and not necessarily with the formation of long term and short term memory.

If a bad ex-girlfriend qualifies as "traumatic" I don't know what to say. The concepts of girlfriends/boyfriends and romantic relationships are cultural artifacts, not products of evolution. Evolution optimizes for mating and reproduction, not individual feelings.

It was merely an example lol