That might be true, but I'm not sure. Outside of local searching I am skeptical of the benefits of filter bubbling.
I think it is just as likely that you and your brother have different opinions of relevance (even if you were both returned the same exact results unrelated to past activity), and the relevance decisions Google makes more align with your brothers perspective.
I am the creator of one of the search engines [0] named in the post. It will return the same exact organic results no matter who you are or what your prior searches were. Feel free to give it a go with your brother and see how it compares for both of you. For organic results, it works like DuckDuckGo does with Bing, but the difference is the main source of our organic results are actually from Google.