I tend to lean more towards assertive, with passive coming in a close 2nd. I think I was passive most of my life (and terribly miserable) until I learned about the various ways to communicate. Then I made a concerted effort to communicate in a more assertive manner. I would be lying, though, if I didn't also own those times that my communication was aggressive; I think I went through a brief period where that was my main means of communication and I readily recognized it as a way to protect myself and my feelings.
What I did not see addressed in the article was passive-aggressive behavior/communication. I found this article regarding passive-aggressive behavior/communication at the Mayo Clinic website:http://www.mayoclinic.com/health/passive-aggressive-behavior/AN01563
I have even knowingly been passive-aggressive with certain individuals as a response to their aggressiveness. So I have run the gamut and found that, for me, being assertive in my communication and behavior is preferable, though I am not always successful at it.
Knowing how one communicates and behaves can give much insight and understanding in relationships. I find it helps if I can focus on my own commucation style and stay as close to assertive as possible. Growing up in a highly dysfuntional family, the communication skills were sadly lacking. It wasn't until my early twenties that I discovered the different styles of communication and began using that new knowledge in hopes of creating more open, honest and trusting relationships. It is not an easy task for me to maintain assertive commincation and behavior, but I know my relationships are better when I am able to be assertive.