Interesting. Thanks brainheart and Metaphor. I am very curious about ways that people have used information on their instinctual variants to promote personal growth or achieve goals. Maybe I'll add that to the OP.
Your kisses, sweeter than honey. But guess what, so is my money.
Being so dismally un-sx and having quite strong sp leanings it's been a matter of awareness of how craphouse I am at one-on-one relationships, how I prefer solitude or group settings to something more intimate. There's a few areas in life that I keep coming back to as needing improvement and developing deeper reciprocal relationships is one of them, it's not about being open though, I'm fine with that, it's more specific sx type things. I need separation between me and another person problem with that is I then push against situations where a relationship could go deeper.
Being able to read about sp/so/sx experiences and see where I'm at has allowed me to use the Enneagram language to describe things and gain a better awareness of shortcomings. I've always known I push people away but this knowledge gives me an understanding of when and why so that I can resist my urges to retreat to safe ground when a sx-dom attempts to wear my skin as they so enjoy. (sickos!)
The instincts are about personal priorities/motives/interests... you get the idea.
They are vaguely, vaguely related to the survival instincts, mating instinct, and pack instinct.
One is not exactly a type based on their instincts stacking. All people of one Enneagram type, say type 1, are supposed handle contextually social matters the same way, or self-preservational matters the same way, etc. The difference between the stacking is merely that a person who's I-P-S (usually called sx/sp) is more focused on, puts more resources* into the Intimate/Sexual matters than others, while a S-P-I (so/sp) puts more resources into social matters than the others.
So yes, they are entirely descriptive (and the rest should be, too )
*the word resource is used very loosely.
Go to sleep, iguana.
INTP. Type 1>6>5. sx/sp. Live and let live will just amount to might makes right
IMO instinctual variants have more to do with your social/emotional needs. for instance a sp/sx is going to have relatively need to fit into a group or social circle, but a so/sx type needs this kind of belonging and group interaction to grow and be emotionally healthy. similarly, many sp typed would become psychologically traumatized in if forced into the military draft. most so/sx types would probably be okay psychologically because their psychological need for safety, security and relaxation is less prevelant. similarly, a sx/so type (especially a 2) could feel overwhelming levels of depression without any intimate friends to share his feeling with. many sp/so types on the other hand can never have an intimate relationship in their life and be perfectly fine.
PS: this is my beef with modern psychology. it tries to through people under all these umbrellas like "all people do this" or "all people need this" when it's just not true. everyone has different cognitive and emotional needs (and MBTI, Enneagram and social variant stackings can be very good indicators). that's what I really like about relavent personality tests, they pinpoint these needs that modern psychology labels as "pseudo science" when in reality we are probably 20-30 years ahead of them in many regards.