Step 1

I research things anyway.
The idea of beginning a long-term research project on a single topic is intimidating to me because I don't seek these things out. Lines of research seem as organic as friendships, I know I don't have all the control. Progress occurs if I remain open and engaged, but time flows in seasons.
I am fond of trees.

This last summer I spent a significant amount of time researching the Meyers-Briggs (Personality) Type Indicator. If you are unfamiliar with MBTI, here is a link that explains it better than I am currently able.

The 16 types are combinations of these options:

Introversion/Extroversion

Sensing/iNtuition

Thinking/Feeling

Perceiving/Judging

or abbreviated: I/E, S/N, T/F, and P/J. As an example of a type, mine is INFP.

Many sites devoted to Meyers-Briggs typing focus on trait aspects. They form convincing profiles of each "personality", likely encouraged by the trait-based setup of the type names themselves. While reading through type profiles and possibly internalizing labels such as "The Idealist", "The Artist", or "The Scientist" may be an enjoyable and even helpful pastime, the real meat (in my opinion) is in cognitive functions.
There are 8 functions. Each hypothetical person uses four most often. Which four they prefer define their type. Here's a list of all eight:

Extroverted Feeling (Fe)

Introverted Feeling (Fi)

Extroverted Intuiting (Ne)

Introverted Intuiting (Ni)

Extroverted Sensing (Se)

Introverted Sensing (Si)

Extroverted Thinking (Te)

Introverted Thinking (Ti)

Each type contains a feeling, intuiting, sensing, and thinking function. These are things we all do, but usually not in the same order. There is also a built-in balance between introversion and extraversion. If you identify as an extroverted person, it's very likely that your primary cognitive function is extroverted.
So how do we get from, say, ESFJ to whatever functions it contains? This I have not come to an understanding of yet. However, a few months ago a friend directed me to a MBTI-focused blog which attempted to explain the connections. I and another friend who I showed the explanation to found it to be difficult to follow, and I wish I could say I really understood it. Perhaps the information could be better represented as a choose-your-own-adventure story or a graph resembling a tree. This is something I would like to create and hopefully will, here. But back to the subject of the other blog, the one feature I found to be very useful is a set of images representing the cognitive process of each type. Thus, without understanding how, I know that an ISTJ's functions are:
1. Introverted Sensing
2. Extroverted Thinking
3. Introverted Feeling
4. Extroverted Intuiting

From this point I have mostly ditched the type names and focused on what each function is all about.

It seems I have have a beginning subject. Up next week (unless the muses speak against it): How some cognitive functions seem like superpowers and how that adds to my perception of why some friendships are so great