An account of human “impulsivity” on self-control tasks

Three experiments examined the effects of economic constraint (time restriction—trials restriction) on adult humans' performance on concurrent chained schedules of reinforcement in which terminal links differed both in reward size and pre-reward delay levels. In the first, terminal links offered a long delay (20, 30, 40, 50 sec) followed by 2 points, or a short delay (10 sec) followed by 1 point. Initial links consisted of the same variable interval schedules for each alternative. Subjects showed a conditional sensitivity to increases in delay. Under a time constraint, there was an increasing preference for the smaller reward as the delay to the larger reward was increased, whereas under a trials constraint subjects were totally insensitive to such changes. In the second experiment, this finding was replicated using long and short periods of video game playing as large and small rewards. In the third experiment terminal link parameters remained constant (2 points after 15 sec, or 1 point immediately), but initial link parameters were manipulated (either VI 1-sec, 8-sec, or 20-sec) so that the higher relative rate of reward shifted from being associated with the small reward to being associated with the large reward. Again subjects chose differently under the two constraints. Subjects under the time constraint exhibited a preference for the small reward at all levels of initial link, but under the trials constraint subjects preferred the large reward. Subjects in the time constraint condition thus exhibited a maladaptive insensitivity to changes in the initial link duration. These findings are interpreted as supporting a miscalculation rather than a discounting interpretation of human performance on “self-control” tasks.     

Discrimination of five-dimensional stimuli by pigeons: Limitations of feature analysis

Pigeons were trained to discriminate between stimuli constructed using five orthogonal two-valued features. The stimuli consisted of stylized monochrome drawings of seeds. Two different training procedures (conditional and simultaneous discrimination) were used. In the first two experiments, the discrimination required was between polymorphous categories, in which a positive stimulus was defined as one in which three or more of the five features took their positive values. Discrimination in both experiments was imperfect; the pigeons' behaviour only came under the control of a subset of the available features (one to three in Experiment 1, three or four in Experiment 2). In Experiment 3, single features had to be discriminated, while the remaining features varied. It was found that all five features of the “seed” stimuli could be discriminated, but one of them was exceptionally difficult. The results show that pigeons do not reliably use all the features available to them when making category discriminations. This casts doubts on feature analysis as a basis for the excellent performance pigeons show when required to discriminate between categories of natural objects.     

Touch screen assays of behavioural flexibility and error characteristics in Eastern grey squirrels (<Emphasis Type="Italic">Sciurus carolinensis</Emphasis>)

Behavioural flexibility allows animals to adjust their behaviours according to changing environmental demands. Such flexibility is frequently assessed by the discrimination–reversal learning task. We examined grey squirrels’ behavioural flexibility, using a simultaneous colour discrimination–reversal learning task on a touch screen. Squirrels were trained to select their non-preferred colour in the discrimination phase, and their preferred colour was rewarded in a subsequent reversal phase. We used error rates to divide learning in each phase into three stages (perseveration, chance level and ‘learned’) and examined response inhibition and head-switching during each stage. We found consistent behavioural patterns were associated with each learning stage: in the perseveration stage, at the beginning of each training phase, squirrels showed comparable response latencies to correct and incorrect stimuli, along with a low level of head-switching. They quickly overcame perseveration, typically in one to three training blocks. In the chance-level stage, response latencies to both stimuli were low, but during initial discrimination squirrels showed more head-switches than in the previous stage. This suggests that squirrels were learning the current reward contingency by responding rapidly to a stimulus, but with increased attention to both stimuli. In the learned stage, response latencies to the correct stimulus and the number of head-switches were at their highest, whereas incorrect response latencies were at their lowest, and differed significantly from correct response latencies. These results suggest increased response inhibition and attention allowed the squirrels to minimise errors. They also suggest that errors in the ‘learned’ stage were related to impulsive emission of the pre-potent or previously learned responses.     

Relation of occupational knowledge to career interests and competence perceptions in Italian children

The relations of differential occupational knowledge with interests and competence perceptions in children as well as how these relations were moderated by gender and grade were examined in this study using an Italian sample. Data were collected from samples of elementary school and middle school children (N = 539). The Inventory of Children's Activities—Revised (ICA-R; Tracey & Ward, 1998) was used to assess children's interest and competency perceptions in various activities associated with the Holland's RIASEC types. The Occupational Knowledge Scale (OKS) was created for this study, and consisted of a representative sampling of occupational titles to which children indicated their knowledge. Hierarchical regression results indicated a relationship between knowledge, interests, and competence perceptions in children. With regard to overall knowledge, no relationship was found between general knowledge and either grade or gender. More specific examination of the type of knowledge as it varied across the dimensions of People–Things, and Data–Ideas demonstrated that there appeared to be a specific pattern relating interest, gender, and grade to knowledge of occupations. For knowledge of people relative to things occupations, higher interest, higher grade level, and being female predicts stronger knowledge of people occupations. It was also found that interest in ideas predicts stronger knowledge of ideas occupations, and being male predicts stronger knowledge of high prestige occupations. Generally, competence perceptions did not have a unique relation with one's knowledge of People–Things, Ideas–Data, or Prestige; however, girls who reported higher competence had greater knowledge of ideas occupations.     

Paths from socioemotional behavior in middle childhood to personality in middle adulthood

Continuity in individual differences from socioemotional behavior in middle childhood to personality characteristics in middle adulthood was examined on the assumption that they share certain temperament-related elements. Socioemotional characteristics were measured using teacher ratings at ages 8 (N = 369; 53% males) and 14 (95% of the initial sample). Personality was assessed at age 42 (63% of the initial sample; 50% males) using a shortened version of the NEO Personality Inventory (NEO-PI); the Karolinska Scales of Personality (KSP); and the Adult Temperament Questionnaire (ATQ). Three models were tested using structural equation modeling. The results confirmed paths (a) from behavioral activity to adult Extraversion and Openness (NEO-PI), sociability (KSP), and surgency (ATQ); (b) from well-controlled behavior to adult conformity (KSP) and Conscientiousness (NEO-PI); and (c) from negative emotionality to adult aggression (KSP). The paths were significant only for one gender, and more frequently for males than for females. The significant male paths from behavioral activity to all indicators of adult activity and from well-controlled behavior to adult conformity started at age 8, whereas significant female paths from behavioral activity to adult sociability and from well-controlled behavior to adult Conscientiousness started at age 14. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Discerning reported suicide attempts within a youthful offender population

With suicide being the third leading cause of death among young people, early identification of risk is critical, particularly for those involved with the juvenile courts. In this study of court-involved youth (N = 433) in two Midwest counties, logistic regression analysis identified some expected and unexpected findings of important demographic, educational, mental health, child welfare, and juvenile court-related variables that were linked to reported suicide attempts. Some of the expected suicide attempt risk factors for these youth included prior psychiatric hospitalization and related mental health services, residential placement, and diagnoses of depression and alcohol dependence. However, the most unexpected finding was that a court disposition to shelter care (group home) was related to a nearly tenfold increased risk in reported suicide attempt. These findings are of importance to families, mental health professionals, and juvenile court personnel to identify those youth who are most at risk and subsequently provide appropriate interventions to prevent such outcomes.     

SELF‐OWNERSHIP AND THE STATE: A DEMOCRATIC CRITIQUE

Libertarians often invoke the principle of self‐ownership to discredit distributive interventions authorized by the more‐than‐minimal state. But if one takes a democratic approach to the justification of ownership claims, including claims of ownership over oneself, the validity of the self‐ownership principle is theoretically inseparable from the normative justification of the state. Since the idea of the state is essential to the very assertion (not just the positive enforcement) of the principle of self‐ownership, invoking the principle to discredit a distribution of ownership authorized by the state commits libertarians also to weakening that principle's validity. Put differently, appealing to the self‐ownership principle to circumscribe the state's power to distribute property is problematic when the state is necessary to assert the validity of that principle. This is because anytime the self‐ownership principle is used to undermine a state‐based distribution of property it is also implicitly eroding the ground for asserting its own validity. 1     

Engagement in community activities and trust in local leaders as concomitants of psychological distress among Israeli civilians exposed to prolonged rocket attacks

Background and objectives: Present study, conducted in the aftermath of the 2014 Israel–Gaza conflict, investigated psychological toll of exposure to rockets attacks in a sample of residents of central and southern Israel. Analyses focused on the distress-protective functions of collectively grounded resources: engagement in community activities and trust in local leadership.

Design: This cross-sectional study was conducted between 2 and 3 months after the hostilities.

Method: Participants (N?=?764) were recruited by an online survey company that distributed a questionnaire assessing, in addition to focal predictors, sociodemographic factors and prior exposure to trauma. The outcome variables were post-traumatic stress disorder (PTSD) and nonspecific distress symptoms.

Results: Conservative regression analyses revealed that greater exposure to rocket attacks was predictive of higher levels of posttraumatic stress symptoms. Higher engagement in community activities exhibited a partial trauma-buffering function. However, higher levels of trust in local leaders appeared to exacerbate, rather than diminish, negative impact of rocket exposure on PTSD. Symptoms of psychological distress were not influenced neither by trauma exposure nor by stressor interactions with resources. Trust in local leadership exerted a beneficial main effect on distress.

Conclusions: Collectively based resources are important for coping in times of community-wide stressors, yet their role is complex.