Metta's Intensity and Concentration I noticed that in my meditation on compassion, the beginning is consistently potent (i.e. tears, strong feeling) and the ending is usually less apt (i.e. body agitation, distraction). 

Would the emotional intensity of such a meditation depend highly on concentration? Or, perhaps, would some other aspect explain this, e.g. becoming saturated emotionally early in the meditation?
I noticed that in my meditation on compassion, the beginning is consistently potent (i.e. tears, strong feeling) and the ending is usually less apt (i.e. body agitation, distraction).

Most likely what is happening is when you think about different people


your perception of them
past incidents
their situations


Stir up emotions.

Would the emotional intensity of such a meditation depend highly on concentration? Or, perhaps, would some other aspect explain this, e.g. becoming saturated emotionally early in the meditation?

Emotional intensity most likely goes down with meditations as your concentration increases your mind becomes stable.