| Concept | Meaning | Relevance to the present study |
| Equifinality Point (EFP) | A point at which diverse paths merge | |
| Polarized EFP (P-EFP) | A point of complementary EFPs | |
| Obligatory Passage Point (OPP) | A point experienced by most people | |
| Social Guidance (SG) | A force that supports movement toward the EFP | [social support] |