How can I list on my CV that I graduated from college in 3 years? Without naming the university (to protect my privacy), I attended one of the top 20 universities in the US for my undergrad and graduated in 3 years with honors. While graduating from this school in 3 years isn't impossible, it's certainly rare. On top of that, I have a good GPA and finished a humanities-based CogNeuro major, a Writing minor, and all my pre-med coursework. 

Now I'm applying to grad school for CogNeuro, and I'd like to highlight the fact that I graduated in 3 years on my CV, for 2 reasons. First, I genuinely think my accomplishments are made more impressive by that fact. And second, because it explains why I have less research experience than some of my peers. So I guess my question is twofold: Should I even bother mentioning that I graduated early, or am I just being arrogant in doing so? And if that's a good thing to mention, how can I do so without being heavy-handed?

Currently I have my high school name and graduation year listed under my "Education" section, not because my high school matters, but because it's the only way I can think of to show that I graduated from college early.
There are no magic words - you just say that thing you want to say.  The simplest way would be simply to specify the years you attended university, and then explicitly note the achievement you want to highlight.  One thing to note is that there is little point in mentioning this unless you have some statistical evidence that graduating within three years is actually a genuine achievement.  Try something like this:


  Education
  
  Bachelor of Doing Things (Oxbridge University) (2016-2018) Graduated with a GPA of 3.61 and won an award for being the top student in my third-course on doing good things.  I was in the cohort of 3% of student who successfully complete this degree program within three years.