The effects of expected and unexpected stress on inappropriate aggression in simulated police interventions
A short warning lowers aggression under stress; surprises spike it.
01Research in Context
What this study did
Farkas et al. (2023) ran a lab game with police cadets. They added stress at set times. Sometimes the cadets got a 30-second warning. Other times the stress hit without notice.
The team counted aggressive button presses and tracked heart rate. They flipped the warning and no-warning phases back and forth in an ABAB design.
What they found
Warnings cut aggression. Sudden stress raised it. Heart-rate jump was the best predictor of who lashed out.
Mixed results mean timing matters more than how hard the stress is.
How this fits with other research
Old animal work said the same. Vukelich et al. (1971) showed low-intensity but frequent shock lowered biting, while rare but strong shock raised it. Farkas adds the human twist: a heads-up acts like the "frequent, mild" cue.
Kelly et al. (1970) used an ABAB lab design with teens. Extinction made punching rise. Farkas repeats the design but swaps extinction for surprise stress. Both spike aggression, so sudden loss and sudden stress look alike.
Bowe et al. (1983) cut playground fights with organized games. Farkas cuts aggression with organized warnings. Together they say antecedent structure beats reactive consequences.
Why it matters
You can’t shock clients, but you can warn them. Tell a learner "in two minutes we start the hard math" or show a visual timer before a demand. That tiny preview may stop problem behavior better than any timeout. Try it next session and track heart rate or response count to see the change.
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02At a glance
03Original abstract
Here we performed a before-after ABA-design study in police cadets (N = 82) to compare the effects of unexpected (event-triggered) and expected (anticipatory) stressors on aggression. On the first day of the study, participants filled in the Buss-Perry Aggression Questionnaire (BPAQ) and the Barratt Impulsiveness Scale (BIS) and were fitted with heart rate (HR) monitors, which remained attached till the end of the study. On day 2, they were instructed to perform a police intervention in a realistic training environment. The intervention was preceded either by a warning or by a reassuring audio recording that forecasted violent or routine interventions, respectively. Both groups encountered hostile suspects at the intervention site, the behavior of which, however, did not justify the use of force e.g., aggression. The warning resulted in a gradually developing anticipatory stress as shown by HRs. Cadets exposed to the reassuring audio recording showed minimal anticipatory stress but responded to the hostile suspects by an abrupt increase in HRs, which was missing in the warned group. The magnitude of HR responses was similar in the two groups, only their temporal evolution differed. Although aggression showed some associations with BPAQ and BIS scores, the main predictors of behavior were HR changes according to a Multiple Regression analysis. The gradually developing anticipatory stress was associated with low, whereas the abrupt increase in HRs was associated with high aggression. Our findings suggest that the anticipation of a stressful event improves behavioral control whereas an unexpected stress strongly promotes aggression.
Heliyon, 2023 · doi:10.1016/j.heliyon.2023.e17871