The mystery of why married men behave better seems to have been finally unraveled thanks to the Michigan State University scientists.
S. Alexandra Burt and colleagues found that less antisocial men were more likely to get married. Once they were wed, however, the marriage itself appeared to further inhibit antisocial behaviour.
"Our results indicate that the reduced rate of antisocial behavior in married men is more complicated than we previously thought.
"Marriage is generally good for men, at least in terms of reducing antisocial behavior, but the data also indicate that it's not random who enters into the state of marriage," said Burt.
The study found that men with lower levels of antisocial behaviour at ages 17 and 20 were more likely to have married by age 29.
Once the men were married, rates of antisocial behaviour declined even more. When comparing identical twins in which one twin had married while the other had not, Burt said, the married twin generally engaged in lower levels of antisocial behaviour than did the unmarried twin.
Another factor that seems to be important is marriage quality; the effect of marriage on antisocial behaviour tends to be stronger in better marriages.
The findings were published in the Archives of General Psychiatry.