Science used to be about the objective facts but since the acceptance of quantum theory, it is more about probabilities than certainties. The data we collect is to some degree changed by the method of observation of the data Heisenberg Uncertainty Principle). Also, which data is collected and which is ignored is where subjectivity enters the equation. Until very recently drug trials were conducted on male subjects only because the researchers didn't want to take into consideration the problems of the female hormonal cycle. Nevertheless, the drugs were assumed to be effective and safe for women if they were so for the men.
Brain science has not yet established how we become self aware although its development in children can be observed and tracked. Baroness Susan Greenfield is working on this
http://www.susangreenfield.com/science/consciousness/ She is looking for an answer to the question "
How do we generate consciousness and an awareness of our own identity?"
She may succeed in demonstrating the validity of her ideas about
‘neuronal assemblies' but at the moment when she talks about these ideas she is speculating, but many people aren't aware that she may or may not be correct. Listen to her talk here to see what I mean
https://www.youtube.com/watch?v=k_ZTNmkIiBc
(I haven't listened to her talk without interruption so I'm not commenting on the content just yet. I probably won't be able to even after listening very carefully because this is foreign territory for me. I do like that she puts her faith in falsifiable hypotheses))