When people are anxious they tend to narrow their thought processes, concentration upon aspects directly relevant to a problem. This is a useful strategy in escaping from danger, but not in thinking of imaginative new approaches to a problem.

Donald A. Norman
Donald A. Norman

An American researcher, professor, and author (The Design of Everyday Things). As Apple’s User Experience Architect (90's), he became the first person to have UX in his job title.

“Fire,” yells someone in a theater. Immediately everyone stampedes toward the exits. What do they do at the exit door? Push. If the door doesn’t open, they push harder. But what if the door opens inward and must be pulled, not pushed? Highly anxious, highly focused people are very unlikely to think of pulling.

Emotional Design: Why We Love (or Hate) Everyday Things
by Donald A. Norman