OK, now that I've finished saying something about each of the 9 Enneatypes, I can begin to explain in more detail what I'm referring to when I speak about the instinctual variants or a person's instinctual stacking. I've heard it stated that one's instinctual stacking is an even more deeply-rooted, influential part of one's personality than one's Enneatype. In any case, this is certainly a very important aspect of the Enneagram system to understand.
The basic concept, as far as I've gathered, is that there are three categories of very fundamental instinctive urges that human beings share with lower animals: the self-preservation instinct, the sexual instinct and the social instinct. We're all pulled into certain attitudes and behaviors by each of these powerful drives to one degree or another, but which of them exerts the strongest, second-strongest and least strong influence on our personality and actions? That is the question that, when answered, lets us know what our so-called "instinctual stacking" is.
I've read -- as well as seen in real life -- that the first two instinctual variants in one's stacking often exert what seems like an almost equally strong influence on a person, while the third and weakest instinct constitutes a sort of "blind spot" for that individual that he or she needs to work on in order to have a more healthy, whole and balanced approach to life. However, it's not always like that; I don't even mean to imply that that's most commonly the case. Many people have one instinct that's unquestionably the strongest in their nature, another that's definitely second and a third that's definitely in last place (with or without constituting a "blind spot" for them), while for some other people, the three instincts are much more closely balanced in their influence on the person (I am under the impression that this last possibility is quite a bit more rare, though). But anyway, the scenario in which two or more instinctual variants are almost equally strong at the top of someone's stacking is good to keep in mind when trying to figure out what a person's stacking is, because it explains why it may be very difficult sometimes to figure out which instinct is strongest in a person's nature based on their values alone, and why, therefore, the energy patterns they exude are a crucial distinguishing criterion.
OK, intro over. Time to get into what sets each instinct apart!
This post (as should be pretty obvious from the title ;D) will focus on the self-preservation, or "self-pres," instinct.
As far as their values are concerned:
Self-pres first people are described as preoccupied with their physical bodies' health, welfare, aches, pains, and sensations, as well as those of everyone else they care about. They're more fussy, particular, or sensitive about the details of their physical surroundings: the light level, temperature, noise level and other things that affect physical comfort tend to be a lot more important to self-pres types than to others. Issues of physical health and safety concerning themselves and everyone they care about will be treated by them as vitally important. They may feel uncomfortable not addressing or treating any illness or discomfort, however mild and nonthreatening it may actually be. Their efforts to eat right, exercise, visit the doctor regularly and take all medications they ought to be taking -- and to make sure everyone else who matters to them does the same (which, with self-pres types, may be limited to a small "inner circle" of family and friends; they tend to prefer a cozier, quieter, more pragmatic and unambitious lifestyle, without excessive social contacts) -- might appear obsessive or annoying to those with differing values.
While self-pres types can certainly enjoy humor, there's a particular brand of crass, juvenile humor that I've read (and observed) that they do not tend to find amusing. Whether that means they are more serious, adult, or refined in their tastes... you be the judge.
Their energy signature (what sets apart those who are authentically self-pres first from those who happen to have a lot of self-pres values in their nature due to a strong self-pres second in their stacking):
People who are self-pres first are said to be quieter, having more of a tendency to keep to themselves than those with other instincts dominant. There
are, of course, completely unrelated personality traits that lead to
such behavior also, such as introversion, self-doubt / shyness, and/or
having withdrawn (4, 5, 9) Enneatypes in one's personality, so being
somewhat quiet and loner-ish does not by any means guarantee that one is
a self-pres first. But regardless of how many of these other traits
are or are not present in a person, being self-pres first tends to make
them more quiet and self-contained than they would be otherwise (i.e. if
they had the exact same personality type except for a different
Due to SP-first types' greater tendency to keep their thoughts to themselves, when their opinions are shared, these are often discovered by others to be thoughtful and valuable contributions to the matter at hand. This is not at all to imply that sexual- or social-first people can't make thoughtful or valuable contributions! But I have the impression from what I've read that being self-pres first does frequently happen to correlate with introversion in people's personalities (though again, those are two separate traits that certainly don't have to coexist in the same person), while the other instinctual variants (or maybe it was just social-first?) have a similar loose correlation to extroversion. And it's well-established that introverts think before they speak, while extroverts generally think while speaking. So although any of these personality types has the potential to be highly intelligent and thoughtful, with self-pres types, there's just a bit more of a likelihood that whatever comes out of their mouths will have already been mulled over and thoroughly thought through, whereas the hastier, more uninhibited personality types might speak half-formed ideas as they occur and might need to polish them up a bit in order to make them fully presentable. ;) Sometimes self-pres-last types, especially (those with sexual / social or social / sexual as the first and second instincts in their stacking), can be downright goofy in their wild lack of inhibition, whereas I sense a lot more restraint and fear of embarrassment in those who have self-preservation high in their stacking. Maybe this, too, has some connection to the idea that self-pres types often speak only that which has been well-considered and is at least somewhat sensible.
All-in-all... quietness, seriousness, sensitivity, and a certain "wallflowerishness" or tendency to fade into the background are energy patterns that may set apart those who are self-pres first from those of other instinctual stackings. (Not to say that all these traits will be present in every SP-first person -- especially not all the time; there are definitely times when SP-first people can be lighthearted and fun, or can exhibit a vividness that will make them the center of attention, for example -- but just as generalities to roughly distinguish these people from others, at least some of these traits may be looked for in SP-first types.)