To sustain or repair cooperation during a social exchange, adaptive creatures must understand social gestures and the consequences when shared expectations about fair exchange are violated by accident or intent. We recruited 55 individuals afflicted with borderline personality disorder (BPD) to play a multiround economic exchange game with healthy partners. Behaviorally, individuals with BPD showed a profound incapacity to maintain cooperation, and were impaired in their ability to repair broken cooperation on the basis of a quantitative measure of coaxing. Neurally, activity in the anterior insula, a region known to respond to norm violations across affective, interoceptive, economic, and social dimensions, strongly differentiated healthy participants from individuals with BPD. Healthy subjects showed a strong linear relation between anterior insula response and both magnitude of monetary offer received from their partner (input) and the amount of money repaid to their partner (output). In stark contrast, activity in the anterior insula of BPD participants was related only to the magnitude of repayment sent back to their partner (output), not to the magnitude of offers received (input). These neural and behavioral data suggest that norms used in perception of social gestures are pathologically perturbed or missing altogether among individuals with BPD. This game-theoretic approach to psychopathology may open doors to new ways of characterizing and studying a range of mental illnesses.

Recent editions of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5; American Psychiatric Association, 2013) conceptualize personality disorders (PDs) as categorical constructs, but high PD co-occurrence suggests underlying latent dimensions. Moreover, several borderline PD criteria resemble Criterion A of the new DSM-5 Section III general criteria for personality pathology (i.e., self and interpersonal dysfunction). We evaluated a bifactor model of PD pathology in which a general factor and several specific factors of personality pathology (PD 'g' and 's' factors, respectively) account for the covariance among PD criteria. In particular, we examined the extent to which the borderline PD criteria would load exclusively onto the g-factor versus on both the g- and one or more s-factors. A large (N = 966) sample of inpatients were interviewed for six DSM-IV (American Psychiatric Association, 1994) PDs using the (Structured Clinical Interview for Personality Disorders (SCID-II; First, Spitzer, Gibbon, Williams, & Benjamin, 1994) with no skip-outs. We ran a series of confirmatory, exploratory, and bifactor exploratory factor analyses on the rated PD criteria. The confirmatory analysis largely replicated the DSM PDs, but with high factor correlations. The "standard" exploratory analysis replicated four of the DSM PDs fairly well, but nearly half the criteria cross-loaded. In the bifactor analysis, borderline PD criteria loaded only on the general factor; the remaining PDs loaded either on both the general and a specific factor or largely only on a specific factor. Results are interpreted in the context of several possibilities to define the nature of the general factor.

The Barratt Impulsivity Scale (BIS), a 30-item self-report measure, is one of the most commonly used scales for the assessment of the personality construct of impulsiveness. It has recently marked 50 years of use in research and clinical settings. The current BIS-11 is held to measure 3 theoretical subtraits, namely, attentional, motor, and non-planning impulsiveness. We evaluated the factor structure of the BIS using full information item bifactor analysis for Likert-type items. We found no evidence supporting the 3-factor model. In fact, half of the items do not share any relation with other items and do not form any factor. In light of this, we introduce a unidimensional Barratt Impulsiveness Scale-Brief (BIS-Brief) that includes 8 of the original BIS-11 items. Next, we present evidence of construct validity comparing scores obtained with the BIS-Brief against the original BIS total scores using data from (a) a community sample of borderline personality patients and normal controls, (b) a forensic sample, and (c) an inpatient sample of young adults and adolescents. We demonstrated similar indices of construct validity that is observed for the BIS-11 total score with the BIS-Brief score. Use of the BIS-Brief in clinical assessment settings and large epidemiological studies of psychiatric disorders will reduce the burden on respondents without loss of information.