Theoretical Approaches to Connection
There are three general approaches to the study of connection experience, an reductionist approach, an adaptive approach, and a transformative approach.
The reductionist approach reduces mysticism, often in a normative and dismissive manner, to neurological/psychoanalytic phenomenon (i.e. an infantile state).
Theorists who take a reductionist approach: Sigmund Freud
The adaptive approach frames connection experiences as healing.
Theorists who take an adaptive approach:
The transformative approach frames connection experiences as capable of leading to profound personal, psychological, sociological, political transformations. 
Theorists who take a transformative approach: Romain Rolland
- Parsons, William B. The Enigma of the Oceanic Feeling: Revisioning the Psychoanalytic Theory of Mysticism. Cambridge, MA: Oxford University Press, 1999. https://amzn.to/2Tq1qsl.