You hear people say that you ought to see an "expert" to get unbiased viewpoints.
Isn't that largely based on the assumption that experts are unbiased? Or is it believed that smarter people in, say, certain fields, are not biased about their knowledge and experiences?
Like, for example, someone has trouble raising their difficult child, and are in need of guidance somehow. What they do is they get the help of a child psychologist/etc. What they're hoping for is help to raise their kids, teach them to behave better, etc., and would rather have the experience of a professional instead of a non-professional because they believe, likely, that it's going to be more beneficial than not.
A child psychologist, however, can be extremely biased about how kids should be raised, and have very strong opinions as well. In fact, they can tend to be more biased than "non-experts" because they have more knowledge on possibilities, and can fixate on their own methods of practice very strongly.
I'd assume that all answers to this question are going to be biased somehow, even if minimally. Why? Because the conjectures, opinions, and beliefs passed on by people are gained and attributed to life experience and personality, which are both shaped by odds, chances, genetics, and so forth.
A saying goes that no one is ever perfectly unbiased. A man says that cars run better when they have lots of gas in them. Is that because he proved this, it's generally "true", or because he's biased?
I give my kid candy and they stop crying. Am I biased if I tell others to do the same? Not all kids will stop crying for candy. What about growing up and having a horrible childhood? Am I biased if I tell others that childhood is horrible, simply because my experience went that way? Or with professionals, would an entry-level engineer be biased about how something could be built? After all, they're only going by what they know so far, and not by what's theoretically possible. This may sound pedantic, but consider it.
All cars will not indefinitely "run better" just because they have more gas. A doctor's opinion is not a final answer always. My terrible childhood isn't a fair example of most childhoods. An engineer can be biased because he/she chooses familiarity over productivity, or "standards" over creative insight to design.