Two-factor theory has strong empirical evidence of validity.

The author re-examined two-factor theory. This theory says avoidance works through two steps: fear drops when you escape, and warning stimuli become safety signals.

Instead of running new lab work, the paper pulls together old data. It shows safety signals act like candy for the brain—they keep avoidance alive long after fear should have died out.

Once a stimulus predicts "no shock coming," it flips from scary to reinforcing. Animals work to keep that safe signal on.

This extra reinforcer explains why avoidance is hard to extinguish. The signal itself is now a prize, not just a cue.

Shimp et al. (1971) first showed pigeons would pay to switch from unsignaled to signaled shock avoidance. Imam (2001) uses that fact as the base for the new safety-signal twist.

Austin et al. (2015) found tokens can wear many hats—reinforcer, cue, or eliciter—at once. The same multi-hat idea applies here: a safety signal is both a cue and a reinforcer.

Green et al. (1986) showed handling cues only boost spontaneous recovery if the bird first learned those cues meant something. Imam (2001) mirrors this: safety signals only reinforce if the learner first links them to shock-free periods.

When you fade avoidance behaviors in kids or staff, kill the safety signal too. If the client still gets the "all-clear" beep, the behavior gets free reinforcement even after shocks (or social negatives) stop. Program extinction for both the escape response and its happy signal.