I meant to type over/under state.
I believe, in aggregate, data can show trends. The cause of these trends is not always clear. Using this example, if it is true that black people, on average report a higher pain number for similar incidents when compared to a different group, that doesn't mean they are lying. It could be that there is a genetic marker that indicates experiencing pain at a higher level. It could mean that past experience with doctors have taught them they need to state their needs as dire to get the care they need. It could mean that more black people can't afford healthcare and as such only go when it is more severe. It may be a cultural phenomena, like how in Britain "man flu" is considered a thing.
I don't believe data says people are lying, I believe data can show a trend. I feel that it is good to be aware of data.