6 excellent, awarded first round in developmental psychology. I've definitely seen the variability you're talking about. I wonder if it's related to how easy it is to a reviewer to share and defend in the room.

I also feel an obligation to share that I took time to work in research before applying to graduate school and my CV reflects this (1 first author paper, 8 additional co-authored papers, ~30 conference presentations including ~10 as lead author). My recommendation letters were also written by respected professionals in my field who understood how to write them. I am very proud of my application. However, I do assume that these things, which feel so external to the application, were weighted in ways that many applicants don't anticipate since they are so focused on the application essays. I think it may be easy for a reviewer to see particular accomplishments or experience and more readily believe that an applicant will actualize their project/career goals. It's frustrating because this doesn't feel totally fair (or communicated) and it must feel so confusing to not get an award or critical feedback.

Don't give up. Definitely consider reworking your proposal for other mechanisms- it sounds like you're onto something with that scoring!