The emotional body — called the astral body in Theosophical tradition — is the second layer of the human constitution, interpenetrating the physical and etheric bodies and extending somewhat beyond them. It is the layer of feeling, desire, emotion and the energetic quality of relational experience. In Theosophical cosmology it operates on the astral plane — a level of reality denser than the mental but subtler than the physical, populated by the forms that thought and feeling create.
The emotional body is the most mobile and most reactive of the bodies — it responds instantly to experience, to other people's emotional states (the phenomenon of emotional contagion operates at this level), to music, to beauty, to threat and to the remembered past. It does not experience time in the way the mental body does — it does not know the difference between a remembered event and a present one. This is why a traumatic memory produces the same emotional response as the original event: the emotional body is reliving it, not recollecting it. This is also why music can transport you instantly to a moment twenty years ago — the emotional body recognises the feeling and re-inhabits it completely.
In the Vedantic framework, the emotional body corresponds to the manomaya kosha (though this is sometimes translated as the mental sheath — the Vedantic categories do not map perfectly onto the Theosophical ones) and to the pranamaya kosha in its emotional dimension. In the Egyptian framework, certain aspects of what the Egyptians called the ba — the soul-aspect that moved freely between the living and dead worlds, that expressed the personality — correspond to the emotional body's mobile, relational quality.
The emotional body is the layer of the self that is most directly affected by relationships — by love, loss, betrayal, attunement, rejection and belonging. It is shaped by early relational experience in ways that persist long after the experiences themselves are forgotten. The attachment patterns identified by John Bowlby and Mary Ainsworth — secure, anxious, avoidant, disorganised — are patterns of the emotional body as much as of the psychological self.