One of the most important things I've learned over the years is how to be a skeptic. Of everything. Personally, I think it comes from spending the majority of my high school years watching Daria, but regardless of origin, it's definitely something that comes in handy from time to time. There are a lot of things people don't think to question. And I don't mean that in a weird, condescending, "people are sheep!!" kind of way, but there are just some things that we are often taught to rely on as objective fact. This includes science and textbooks.
Which, the problem is that science-- as far as I know, anyway-- is done by people. Textbooks are most likely written by people. And all people have biases that they can unconsciously imbue into their work, which many of us then accept as fact without question. For example, you may have heard of doctors diagnosing women who demonstrated certain traits-- usually those regarded as "unfeminine"-- with a variety of mental illnesses (the most infamous of these being hysteria). The "rest cure" (domestic work, among other things) was often prescribed as treatment, with disastrous results. Or, there's also an extensive history of scientific racism. Or the fact that the DSM, the bible of psychiatry, listed homosexuality as a mental illness for decades.
The majority of these examples happened in the past, but unfortunately there's still many traces of those beliefs because they were thought of as fact for literal centuries.
I bring this up mainly because my archaeology textbook is a fantastic example of this. Archaeology is technically an anthropology class-- and in my cultural anthro class, one of the most significant things we learned is the sociocultural implications of being an anthropologist. The idea is, when studying other cultures, to rid yourself of ethnocentric views. Otherwise you end up with incredibly biased observations and that can lead to the misrepresentation of an entire culture. For example: as a result of bias, the roles of women in different cultures have rarely been studied in anthropology. We know NOTHING about them!
So, on to my archaeology textbook. The author talks about the history of archaeology-- which for a while involves a lot of treasure hunting, tomb raiding (and not the video game kind), outright stealing, etc.-- with a tone of glowing nostalgia, and uses a lot of euphemisms and weird justifications for violent European imperialism. Which, alright then. And then he goes on to talk about the subdivisions of archaeological theory and expresses a lot of distaste for the archaeologists who focus their research on, well, those who historically haven't been researched (such as women, ethnic minorities, those who live in what we define as developing countries, etc.).
And I mean, when you think about it, how often do you hear about people who belong to those groups in lessons? They all existed at probably any given point in human history, but in retrospect, it's pretty rare that we ever learned about them.
The author discredits that subdivision as some sort of radical sect of archaeology, something that shouldn't be taken seriously, and my problem with it isn't necessarily that he thinks that, but that this is assigned reading for a large class of students-- many of whom are women and/or ethnic minorities, and who may have families that came from developing countries-- who have been taught to regard this as solid fact. The implication of the author's statements is that there are people who aren't worth studying, who don't deserve a place in history, and I worry that some students may internalize that message as an objective truth.
In case that sounds like an extreme statement, I'll try to put it in perspective: were I an archaeologist, I actually would love to investigate women's roles in history and in different cultures-- partially because I am a woman, and I've never been taught much about them outside of typical domestic (or, like I mentioned, clinically insane) roles. But to be told that my interest in those things is radical/not worth researching/etc. can be more than a little discouraging. And that's as someone who has become very aware that not every word in a textbook is an undeniable fact.
tl;dr I get kind of passionate about bias, and textbooks can be pretty weird about things sometimes.