How to discover the other person's psychology from their mistakes?

Many seemingly accidental errors, such as misstatements, misspelled words, misreading content, or sudden forgetfulness, are not purely coincidences, but the result of two conflicting intentions in the mind.
One intention is superficial, aligned with the realistic situation, and is something people can openly express;
the other intention is more hidden, often carrying genuine but inconvenient psychological tendencies.
When these two intentions interfere with each other in the brain, a person may make mistakes, and precisely at this "point of error," a more authentic thought is concealed.
In other words, if you can capture the specific location of the other person's mistake and strip away the surface-level reasonable explanations,
there is an opportunity to infer the underlying true motive.
However, this method is more of a psychological analysis perspective rather than an absolutely reliable "mind-reading" technique.