Scans the room, startles easily
They sit facing the door, jump when someone drops a file, and pick up every change in your tone.
Rule out first
Past danger that makes watchfulness sensible. Too much caffeine. Security or medical work that trains vigilance. A noisy open-plan office.
What could explain it
Sensory processing sensitivity (highly sensitive person): Sensitive to everything (noise, light, mood) with no history of threat; they're drained rather than afraid.
Hypervigilance: The scanning is for threat, and they relax only in places they know are safe.
Post-traumatic stress disorder (PTSD): Linked to a specific event, with nightmares, flashbacks and avoidance of reminders.
Generalised anxiety: Worry about many things and constant muscle tension; less physical scanning, more mental what-ifs.
Paranoid personality: They scan for hostile intent in people's motives, not for physical danger, and usually find it.
A next move
Notice what they watch. Faces and tone means paranoia or relational hypervigilance; exits and sudden noises means trauma; everything at once means sensitivity.
If it’s you
What am I watching for, and when did I learn to?