[user104658]

A partner etc. no way, unless they were threatening my life or serious injury (e.g. coming at me with a knife or another weapon). For "randoms" - nobody should ever hit anyone else without seriouly good reason. Not "provocation", "wnding up" or whatever... no one should turn to violence unless it's to physically defend themselves or others who, again, are at real risk of being killed or seriously injured. In that case, basically use whatever force is necessary to stop an attacker. Male or female really doesn't matter.

Actually thinking about it there is no gender distinction at all, then. Men should only hit women in extreme and defensive circumstances - but likewise, men should only hit other men in those circumstances .

Or mutually agreed sports, obvz.