Have you tried incognito mode? I also recall there was option to turn off customizing search results (or something similar) in google's privacy settings.
EDIT: I did not notice any differences so I don't really know how to test it. I search highly technical stuff for work or very mundane "popular" things outside of it. Seems like I'm bad target for the customization.
This is a good explanation for why my friends search results are very different from mine. Google would spin this as individualization. Is there any way to get around this bubble and unearth fresh results each search ??