What is my instinctual preference? Subtype and variant stacking
The Enneagram instincts of self-preservation, sexual, and social are traditionally used to describe three variations of type called subtypes. For example, a person who identifies as type 1 can more specifically identify as a self-preservation 1 (abbreviated sp 1), a sexual 1 (abbreviated sx 1), or a social 1 (abbreviated so 1).
The instinctual variant approach views the instincts on their own, independent of type. Although they can also be used with type as well. For instance, two people can be compared as sp-dominant regardless of type or they can be compared as sp 1 vs. sp 2.
Instinctual stacking looks at all three instincts in terms of preference. As an example, if you prefer self-preservation most and social least your stacking would be self-preservation 1st, sexual 2nd, and social 3rd (abbreviated sp/sx, the third instinct is implied by its omission).
Instinctual variant stacking can be used with or without reference to type (e.g. sp/sx or sp/sx 1). When used without reference to type then two people can be compared solely on instinct without considering type.
Distinguishing the approaches
Unfortunately it's not always clear which approach to the Enneagram instincts is being used. People and tests often intermingle the use of the terms subtype, variant, and stacking, not realizing they may actually be referring to different approaches and different interpretations.
The distinction is that instinctual subtype refers to using instinct to solely define three variations of type (e.g., sp 1, sx 1, or so 1) while instinctual variant and variant stacking refers to the instincts separately from type yet may also be used with type as well (e.g., sp or sp 1, sp/sx or sp/sx 1).
similarminds.com - Instinctual Variant Test- Interpretation(s): similarminds.com
- Testing method: Likert scale
- Number of test items: 25
- Test results: Score % for each instinct
- Cost: Free to take the test
- Interpretation(s): Enneagram User Guide
- Testing method: Forced-choice, Paragraphs
- Number of test items: Short version = 2, Long version = 5-7
- Test results: Ranked scores for all three instincts
- Cost: Free to take any test
- Interpretation(s): similarminds.com
- Testing method: Likert scale
- Number of test items: 131
- Test results: Score % for each type, instinctual stacking
- Cost: Free to take the test
- Interpretation(s): Enneagram User Guide
- Testing method: Forced-choice
- Number of test items: 5
- Test results: Subtype scores for a type
- Cost: Free to take any test
- Interpretation(s): similarminds.com
- Testing method: Likert scale
- Number of test items: 102
- Test results: Myers-Briggs type, score % for each Enneagram type, instinctual stacking
- Cost: Free to take the test
- Interpretation(s): Eclectic Energies
- Testing method: Likert scale
- Number of test items: 52
- Test results: Type, wing, and dominant instinct
- Cost: Free to take test
- Interpretation(s): Enneagram Institute
- Testing method: Forced-choice
- Number of test items: 37
- Test results: Score for each instinct
- Cost: Pay to take the test
- Interpretation(s): *Unknown
- Testing method: Forced-choice
- Number of test items: 15
- Test results: Score for each instinct
- Cost: Free to take the test
- Interpretation(s): similarminds.com
- Testing method: Likert scale
- Number of test items: 60
- Test results: Score % for each type, instinctual stacking
- Cost: Free to take the test
*Unknown interpretations are where the test website has no type descriptions and the test itself makes no mention of which interpretation is being used.