Jumping to conclusions
From Volume 11, Issue 6:According to Wikipedia, “jumping to conclusions” (officially the jumping conclusion bias, often abbreviated as JTC, and also referred to as the inference-observation confusion) is a psychological term referring to a communication obstacle where one “judge[s] or decide[s] something without having all the facts; to reach unwarranted conclusions.”
JTC has caused me more grief than any other Knower/Judger reaction I can think of.