To Rez:
I don't have a lab, so I have to accept most scientific claims based on trust in authority. I use rules of thumb:
The major non-controversial theories that are simple enough that I can understand "from the armchair" also tend to be repeatable in classrooms. If it's in an elementary textbook, then I feel certain that the claim has practical value.
The most recent theories tend to be complicated, so I don't waste a lot of time with them. Instead, I let others decide if they are worthwhile and hope for products.
I tend to put low weight to 'evidence' that comes from complex computer simulations. Anecdotal experience with past simulations accounts for this low certainty. This is especially true for chaotic systems, like global weather.
I consider theories that explain the distant past to be interesting but highly uncertain. The claim 'we are evolving' gets higher certainty than 'we evolved from X'.
I don't question the promise of technology that is widely distributed. I tend to have a 'wait and see' attitude on tech that is not yet developed. I may review it and think 'gee whiz' or 'yeah right' depending on how far-fetched it is. If some invention has great practical value to the masses but isn't being mass produced then it trips the BS meter in my mind.
I'd rather upgrade something considered uncertain to a more certain status later on than downgrade something I thought was certain to the BS status. The former makes me feel like I'm learning. The latter makes me feel like I'm gullible.
I always take dietary studies with a grain of salt (even if they are low sodium diets).
