Now interestingly, if I look at *my* search history, only my results show up. In fact, they don't even seem to be shared between devices, as entries from the phone don't show up when I look in the laptop, and vice versa. read more
My wife's phone is the same and on the same account. I have two other phones on the account as well. Recently, I noticed that searches my wife is making on her phone are showing up in my search history (only her searches, not any of the other two phones that are iPhones). read more
But I've now noticed that all the Google searches I do on my PC (using Firefox while logged in to my gmail account), appear in the search history on a Google app on my phone, and presumably my wife's phone (uses same account, but I haven't checked. read more
You are using your google account when you are searching things. IPhone requires you to use a gmail for activating. Just like how when you clear your search history on your phone, it clears it on your computer ad well. Maybe log off your account or just clear your searches or go to settings under google. read more