IMHO the difference is time. When you are single in college or just out of school, you can socialize every night. When you are married, and have kids and a demanding job, you barely have enough time for existing obligations. Just less time for new social bonds, or they come at the expense of old ones.
I used to have 2x the personal social network connections (Facebook) than professional (LinkedIn). Now it's flipped.
I used to have 2x the personal social network connections (Facebook) than professional (LinkedIn). Now it's flipped.