When the response does not match the threat: The relationship between threat assessment and behavioural response in ambiguous lethal force decision-making

Not according to plan: Cognitive failures in marksmanship due to effects of expertise, unknown environments, and the likelihood of shooting unintended targets

Shooting errors have multi-faceted causes with contributing factors that include sensorimotor activity and cognitive failures. Empirical investigations often assess mental errors through threat identification, yet other cognitive failures could contribute to poor outcomes. The current study explored several possible sources of cognitive failures unrelated to threat identification with live fire exercises. Experiment 1 examined a national shooting competition to compare marksmanship accuracy, expertise, and planning in the likelihood of hitting no-shoot or unintended targets. Experts demonstrated an inverse speed/accuracy trade-off and fired upon fewer no-shoot targets than lesser skilled shooters, yet overall, greater opportunity to plan produced more no-shoot errors, thereby demonstrating an increase in cognitive errors. Experiment 2 replicated and extended this finding under conditions accounting for target type, location, and number. These findings further dissociate the roles of marksmanship and cognition in shooting errors while suggesting that marksmanship evaluations should be re-designed to better incorporate cognitive variables.

How speed impacts threat assessment in lethal force decisions

Despite the importance of being both fast and accurate in lethal force decisions, there is little empirical evidence to identify how speed impacts threat-related decisions and perception. Two experiments used speeded and unspeeded manipulations to determine how the speed imperative impacted threat assessments. Experiment 1 used drift diffusion modeling to quantify decision parameters, including rate of information processing, decision threshold, bias, and non-decisional processes. Speeded conditions reduced the information threshold needed to make decisions and shortened non-decisional processes, yet this manipulation had no impact on the rate of information processing or starting bias. Experiment 2 explored perceptual differences in threat assessment. Participants confidently made threat assessments despite only 30 ms exposure to stimuli with little impact on their subjective threat ratings based on exposure duration. Taken together, these results document the influence of speed on decision-making parameters of threat assessments while demonstrating little impact on threat perception.

Perception Over Personality in Lethal Force: Aggression, Impulsivity, and Big Five Traits in Threat Assessments and Behavioral Responses due to Weapon Presence and Posture

The use of lethal force is a combination of threat perception and individual judgment that sometimes warrants a behavioral response. This simplified description implicates perceptual factors and individual differences in lethal force decision making, which ongoing research continues to address. However, personality-based factors have been less explored as to how they might affect either threat perception or behavioral responses in a lethal force decision. The current investigation examined multiple personality traits with the potential to influence lethal force decision making, including aggression, impulsivity, and the Big Five traits. These measures were compared to threat perception and behavioral responses made to a variety of lethal force stimuli broadly categorized as clear threats, ambiguous threats, and clear nonthreats. Samples were recruited from combat-trained infantry, military recruits, and the civilian community to control for prior lethal force training. Although there was a strong omnibus relationship between threat perception and the likelihood of a behavioral response, neither military training nor personality differences had any impact on threat perception or a binary (e.g., shoot/don't-shoot) behavioral response. Therefore, we conclude that perception dominates personality in lethal force decision making when the threat assessment decision is limited to factors such as weapon presence or posture rather than emotion.

The missing consequences: A fourth flaw of experiments

Decisions are affected by the potential consequences as much as any factor during the decision-making process. This prospective influence represents another flaw overlooked by most experiments that raises questions about the use of certain laboratory paradigms. Lethal force encounters are a prime example of this problem, where negative consequences of slow decisions and wrong decisions should be considered alongside behavior.

The role of inhibitory control in shoot/don't-shoot decisions

Previous work has demonstrated a link between cognitive abilities, specifically inhibitory control and lethal force decision-making performance. However, many previously used approaches to simulating shoot/don't shoot scenarios have lacked ecological validity. There is a need to investigate how inhibitory control impacts shoot/don't decisions using realistic simulations to better translate the findings to military and law enforcement settings. This study used multiple cognitive control tasks incorporating discrete judgements in go/no-go and stop signal tasks as well as subjective judgements in go/no-go tasks with both colour stimuli and emotional faces. These combined tasks provided a comprehensive evaluation of inhibitory control abilities. To ensure ecological validity in shooting performance, existing military training scenarios incorporated realistic weaponry and aiming behaviours across different shoot/don't-shoot simulations. The inhibitory control battery identified five principal components from the various tasks, including: stopping ability, response speed, emotion detection, colour detection, and emotional biases. These principal inhibitory control components were entered into hierarchical linear regressions with the dependent variables of unintended casualties inflicted and lethal rounds fired, respectively. Stopping ability better predicted the likelihood of inflicting an unintended casualty, whereas response speed better predicted the number of lethal rounds fired. These regression models included baseline metrics of marksmanship and shots fired, which supports a role for inhibitory control above and beyond basic shooting abilities or strategy. These collective findings provide mechanistic support for the relationship between inhibitory control and errors in shoot/don't-shoot decision-making while using realistic military training scenarios.

Developing scenarios that evoke shoot/don't-shoot errors

Multiple errors can occur in a use-of-force scenario, although some critical errors involve unintended casualties where the target should never have been fired upon. Training instructors utilize a variety of methods to ensure military and law enforcement personnel do not inflict unintended casualties. However, there is little empirical evidence about the best methods to design a shooting simulation that might evoke these errors, which is critical to ensure the validity of any assessment or training exercise. The current study analyzed performance across a variety of simulated shooting scenarios developed and applied for military training purposes. Several factors were assessed based upon either the scenario or human performance. Scenario type, number of shots fired, and the ratio of hostiles-to-non-hostiles were significant predictors for the likelihood of inflicting an unintended casualty. This collected evidence should help improve scenario design for future training simulations that will help avoid these critical shooting errors.