Bias towards the first version you have heard, Primacy Bias?

I have noticed a strong tendency for people to believe facts, explanations or accounts that are the first version they have heard. Even when more or better evidence is presented later it seems much harder to overturn an existing belief than establish a new one.

I would call this the primacy bias. Is there a more widely accepted name and is there an except explanation of this?

I have noticed a lot on my recent girlfriend where for example, when she heard that US money was green because of that color best-evoked trust, but when I showed her psychological literature that showed blue was most strongly associated with trust. That color theory had not been developed at the time the greenback was inaugurated, and that there were explicit anticounterfeiting reasons documented with the green ink dollars were printed with her response was to question the credibility of my sources rather than examine the credibility of the sources she heard that original assertion from.

In psychology, there is a cognitive bias know as the primacy effect , which is the strong tendency for people to remember the first item on a list, first idea presented, first impressions, etc. I don't know of any literature that supports the fact that is also affects belief. However, it is plausible that it does indirectly through the availability heuristic . The availability heuristic is the tendency to use/believe those ideas that most easily come to mind and if through the primacy effect, the ideas that first come to mind are the first, then we have this link. But there is also the recency effect , which is the inverse of the primacy effect, so through that bias, it is plausible that people would believe the last (or most recent) thing they hear. Again, I am just throwing out possibilities here. As far as I know, there is now clear indication that we tend to believe the first things we hear. What you might be noticing is simply the difficulty of undoing a strongly held belief.