have a good head on shoulders
have a good head on (one's) shoulders
To be capable of making sound, responsible decisions. Joe has a good head on his shoulders, so I highly doubt that he would go to Vegas and gamble all his money away.
have a good head on one's shoulders
Fig. to have common sense; to be sensible and intelligent. Mary doesn't do well in school, but she's got a good head on her shoulders. John has a good head on his shoulders and can be depended on to give good advice.
good head on one's shoulders, to have a
To be intelligent or shrewd. This term began life in the sixteenth century as having an old head on young shoulders, meaning a young person who has an old person’s wisdom. Sometime in the course of time “old” was clarified into “good,” although in the nineteenth century it was also put as simply having a head on one’s shoulders.