I have seen an article in TIME website regarding this. I started thinking and relating to many people whom I know and have changed to less anti-social. The statement seemed so true. A good marriage civilizes men.
Once the men are married, they start taking more and more responsibilities. The agression starts converting to passiveness. They tend not to get involved in any illegal activities. They stop eating outside food and reduce boozing which would improve their health when compared to what they were as bachelors. Men start thinking about cars for bikes after marriage for different reasons and one among them would be safety.
I felt that many men stop or reduce socialising with friends which would actually not give them a chance to think about anything other than the family responsibilities. This would reduce right from fist fights between the friends to drunken driving with the friends to racing on the roads with them.
As men grew older with the marriage, that also would play a significant role in these changes in men. At the end is this change for good or bad – Definitely for good.