No doubt people are influenced by their expectations, which are created by past observations. For example, whenever my dog sees a rabbit, she chases it, so I expect the dog to chase any rabbit that she sees. As a result, when I am walking the dog and spot a rabbit, I hold on more tightly to the leash. I have learned what to expect from that dog.
If I see Stephen Colbert on my screen I expect a joke. If I see Donald Trump or Kellyanne Conway on my screen I expect anything but the truth. All three of these people have built these expectations through their behaviors. Most of us had no expectations of these people until they started publicly creating their own images.
I am not biased against Stephen Colbert, Donald Trump, Kellyanne Conway or my dog. I just know, from long experience, what to expect from each of them.