Abstract: Systems and methods for inter-population assessment of neurobehavioral status employ neurobehavioral profiles to accommodate differing external conditions. Population profiles and external condition data are provided to a neurobehavioral performance model to determine neurobehavioral status under external conditions. Alternatively, neurobehavioral performance values may be retrieved from the profile when such values are stored in conjunction with external condition data. Comparisons of the resulting neurobehavioral status(es) are then determined, and may comprise without limitation one or more of: performance deltas, statistical parameter differences, rankings, above/below performance threshold determinations, pass/fail indicators, and countermeasure recommendations. Populations may comprise pluralities, individuals and empty (“null”) sets. Comparisons may also pertain to one or more relevant times of interest and one or more sets of testing conditions.