Any search engine, and Google including, gives out results and preliminary input based on the previous activity of the user. That you want to see is offered to you.
What to receive basic output it is necessary to come every time from the new address and the browser with pure history. Thus the second output will already consider the first, and in half an hour of Google will be aims not to let out you from a circle you set.
Such system is called - a bubble of filters.