SS, I think the changes can occur both from the maturation process and also from conscious decisions. I've had to push myself to do things even though they were very difficult, and the more I forced myself to do things, they easier they became. It will never be as comfortable or easy for me to relate socially as it is for someone with a basically outgoing personality, but it is easier.
Becoming more mature also helps, though. But, again, maturity doesn't just happen, you need to nurture it. There are those who simply grow old, still keeping all the same concepts and ideas they had when they were adolescents. If you allow yourself to ponder your experiences and to grow, then you truly become mature.
Tigger....I remember the same paradigm occurring when I was younger. I honestly believed that young brothers were looking for a wife who was spiritually strong and intelligent. It constantly amazed me to see the bimbos getting the guys. These girls were really into makeup, clothes, and "putting out" as much as they needed to to snag a guy.
I can remember going on a date with the son of an elder from another congregation. We went to an amusement park. It was kind of nice having him sit close to me on the rides, put his arm around me on the scary ones, and hold my hand. But, when we got into the Fun House and I was constantly being attacked by "breast spiders" and "hiney rhinos" in the dark, I started to get really unnerved. The goodnight kiss was.....well, let's put it this way....I never realized anyone's tongue could be so long.
As a "good JW girl" I tried to maintain a proper Christian relationship. Needless to say, he never asked me out again.