Mitch Jacinto:
hello
ive been able to observe something like this the past few weeks, (2nd path), when i approach a situation where i have to protect myself, i.e. trying to not be drawn to reactions of people, oor when im trying to maintain composure. as an instinct/karma, i do a equanimity jhana. i.e. im walking down the street and i keep feeling a concentrated state like equanimity and i feel sort of stable/hard to distract
is this the equanimity state described in brama vihara's?
do anyone here experience this and cultivate it and use this and use this a lot?
thanks a lot

This is an old question, but still listed as "awaiting an answer." I am not a scholar of the brahma viharas by any means but I have some practical experience with them.
Equanimity, or
upekkha, is the only one of the four
brahma viharas that in its classical formulation is not a bestowal (on oneself or others) but a statement of a fact. What do I mean by this? Well, the formulation of
upekkha when cultivated as a brahma vihara is, "You are the guardian of your karma. Your happiness and unhappiness are dependent on your actions, and not on outside forces." In contrast, if one cultivates, say,
mudita for another, the formulation (when one is still using words) is "May your good fortune continue and increase." If you are cultivating
karuna, the formulation is, "May you be free from suffering and its causes." These are bestowals of good wishes on other people (or oneself).
If you are in a situation where you are protecting yourself, a reminder to yourself that "I am the guardian of my karma. My happiness and unhappiness are dependent on my actions....etc. etc." can very likely be calming and soothing, which is what you have observed, but it is certainly not the only way to decrease reactivity. "Stable and hard to distract" could be access concentration, although the context is unusual.
It is also true that
upekkha is the factor that comes to the forefront as one works one's way up the samatha jhanas from the first to the fourth, but
upekkha is not the only factor present in the fourth jhana, nor does the conscious cultivation of
upekkha place one is in the fourth samatha jhana automatically.
Upekkha can begin to arise spontaneously in daily life after conscious cultivation. This may be what you are experiencing.
Just to make matters more complex, there is a vipassa jhana along the Path of Insight called Equanimity in which this quality may occur, but this is not directly related to concentration practice.