One of the many things I have been puzzling over lately is the psychological phenomenon in which people have trouble remembering that groups are made up of individuals.

Examples include stories such as this one, about a town where people are shocked to discover that their vote to summarily expel all undocumented immigrants means a great friend and pillar of the community is getting deported, or this one, about people who are stunned that their vote to repeal the law that gave millions of people access to health care might result in the removal of their friends’ and neighbors’ access to health care.

My most acute awareness of this phenomenon has been when I have lived in countries in which many people were prone to anti-American jokes, statements, or even rants, which they would follow with, “but not you” or “you don’t seem like an American.” Probably most of us have experienced something like that after someone made a joke or a sweeping generalization about our ethnicity or gender or some other group to which we belong.

It makes sense for our brains to categorize things. It’s part of the pattern recognition processes that allow us to function as human beings. I don’t think it’s possible, or even desirable, for us to stop doing it, but I do think we need to be aware of it, and use that awareness to help us make decisions.

One group I might have a tendency to de-individualize in this way is Trump supporters. I do get exasperated with people like those in the stories mentioned above, and yes, in private, I sometimes (okay, frequently) make sweeping generalizations that may be unfair.

The thing is, I am aware, when I am doing that, that I am doing that. I understand that many people’s experiences in life have been very different from mine, and that those experiences have led them to draw very different conclusions. I have plenty of sympathy for them, and for their suffering.

Therefore, when I come across individuals who are Trump supporters, but who are also nice, hardworking, decent, even kind human beings, I am not particularly surprised. I am deeply, deeply frustrated, but not surprised.

I am frustrated because, long before the election, Donald Trump made it excruciatingly clear that he lies constantly, feels no loyalty to anyone, cares about no one but himself, is incompetent in almost every conceivable arena except self-promotion, and is in almost all respects abominable. All of these conclusions can reasonably be drawn solely from evidence gleaned from his own statements, both spoken and tweeted. I am frustrated not because I don’t understand people’s reasons, but because none of those reasons is good enough. They seem to see him so much as a member of their group that they ignore the fact that he is a particularly terrible individual.

Of course this is not true of all Trump supporters. Some are fully conscious of how horrible he is and like him all the more because of it, and some are confused or misguided for other reasons, but many have succumbed to this tendency to think in terms of groups instead of individual human beings. How do I know this is true of a number of people I have never even met? I know because when they discover that someone who entered the country illegally, or who can’t afford healthcare, is a nice, hardworking, decent, even kind human being, they are surprised.