India, Oct. 23 -- It started out as a rather simple function. It's strange how much search has changed, and how it is changing us.

There is probably no digital record more intimate than a search history. Our social media is carefully curated. Even private messages are written for someone else. Search may be one of the few non-performative things we still do online: a record of questions asked without an audience, often before we have decided whether a thought is worth saying aloud.

British data journalist Simon Rogers's new book, What We Ask Google, begins with the proposition that this peculiar archive can tell us something about ourselves.

Drawing on two decades of Google data, he treats this function as a social mirror, and what he ...