Moderate your behaviour appropriate to the situation or circumstances you are in.
If boys were skylarking about, running and whooping, playing some kind of catch-me game inside a church, then the priest might remind them, this is the House of God - please govern yourselves accordingly. (That is, you don't carry on like that in a church - you are quiet and show reverence.)
or
The headmistress of a girls' school might remind them before a school outing that they are pupils of a highly respected school and that they should remember at all times that they are 'ladies' and govern themselves accordingly.