How do we model the actions of those around us? This problem has been crucial for human survival since before the Holocene, so the brain has developed clever tricks to solve it. Personal attributes emerged as one of these tricks, as reflected in language: Bob is reliable, while Sally's a perfectionist. When these attributes are extended to groups, they become stereotypes: politicians are liars, but priests are honest.
This allows us to categorize people and then predict the actions of any person with a certain attribute. Rather than ask, "What would Bob do?" we ask, "What would a reliable person do?" It becomes unnecessary to examine individuals.
This type of reasoning creates problems. On a small scale, it can cause prejudice, rash judgement, and hurt feelings. On a large scale, it can lead to demographic conflict, systemic bias, and social ruin. We can do better! How can we reliably predict the others' actions without relying on stereotypes?
The answer is to look directly at the data—previous actions. While we already use past actions to justify given attributes, I propose cutting out the middleman and using previous actions to directly predict future ones. Rather than trusting Bob to protect a keepsake because he's reliable, trust him because he has always returned borrowed items quickly. Instead of calling a public figure a liar, show that past claims have been false 15% of the time, and make a prediction.
When using past actions to predict future ones, use actions that are as closely related as possible to what you want to predict. For example, the fact that Bob return books quickly doesn't necessarily mean he will come to your meeting on time, even though both would traditionally indicate reliability.
We can extend this beyond people to replace many more vague attributes with specific observations. One example is saying, "Mathematics involves extreme precision and abstraction" instead of "Mathematics is difficult." It's important to understand that attributes are nothing more than a shortcut: a more accurate option is always available. This is the same idea underpinning both E-prime and the writing rule show, don't tell.
Once thinking in this way becomes the default, mental impressions of both people and situations become more specific, more actionable, and simply more accurate.