Similarity, feature discovery, and the size principle

In this paper we consider the “size principle” for featural similarity, which states that rare features should be weighted more heavily than common features in people’s evaluations of the similarity between two entities. Specifically, it predicts that if a feature is possessed by n objects, the expected weight scales according to a 1/n law. One justification of the size principle emerges from a Bayesian analysis of simple induction problems ( [Tenenbaum and Griffiths, 2001a] and [Tenenbaum and Griffiths, 2001b]), and is closely related to work by Shepard (1987) proposing universal laws for inductive generalization. In this article, we (1) show that the size principle can be more generally derived as an expression of a form of representational optimality, and (2) present analyses suggesting that across 11 different data sets in the domains of animals and artifacts, human judgments are in agreement with this law. A number of implications are discussed.     

The effects of mortality salience on political preferences: The roles of charisma and political orientation

Research has shown that mortality salience (MS) heightens liking for certain political candidates. Yet the particular qualities that make candidates more appealing after MS has been subject to debate. This study tested three possibilities: MS increases liking for charismatic candidates independent of participants’ or candidates’ political orientation; MS increases liking for conservative candidates independent of participants’ or candidates’ political orientation; and MS increases liking only for charismatic candidates who support the individual’s pre-existing political orientation, whether liberal or conservative. Following a MS manipulation, liberal and conservative participants evaluated two hypothetical gubernatorial candidates who differed both in their political orientation and level of charisma. MS heightened liking of charismatic candidates who shared the perceiver’s political orientation, whether liberal or conservative. In contrast, MS reduced liking for uncharismatic and opposing-orientation candidates. Results thus indicated that MS heightens regard for same-political orientation charismatic candidates, rather than just any charismatic candidate or conservative candidates. Implications for the influence of death-related concerns on political preference are briefly discussed.     

An investigation of the generalizability and dependability of Direct Behavior Rating Single Item Scales (DBR-SIS) to measure academic engagement and disruptive behavior of middle school students

A total of 4 raters, including 2 teachers and 2 research assistants, used Direct Behavior Rating Single Item Scales (DBR-SIS) to measure the academic engagement and disruptive behavior of 7 middle school students across multiple occasions. Generalizability study results for the full model revealed modest to large magnitudes of variance associated with persons (students), occasions of measurement (day), and associated interactions. However, an unexpectedly low proportion of the variance in DBR data was attributable to the facet of rater, as well as a negligible variance component for the facet of rating occasion nested within day (10-min interval within a class period). Results of a reduced model and subsequent decision studies specific to individual rater and rater type (research assistant and teacher) suggested degree of reliability-like estimates differed substantially depending on rater. Overall, findings supported previous recommendations that in the absence of estimates of rater reliability and firm recommendations regarding rater training, ratings obtained from DBR-SIS, and subsequent analyses, be conducted within rater. Additionally, results suggested that when selecting a teacher rater, the person most likely to substantially interact with target students during the specified observation period may be the best choice.     

Examining the Potential of Community-Based After-School Programs for Latino Youth

Results are presented from two pilot studies examining the potential influence of community-based after-school programs (ASPs) on regionally diverse Latino youth of varying ages. Study 1 examined relations between dimensions of ASP attendance and content, and ethnic identity development, and self-worth in urban Latino adolescents. In this study, higher ratings of the ASP’s emphasis on ethnic socialization were associated with a more developed ethnic identity, while greater intensity of ASP participation and perceptions of ASP quality were associated with higher levels of self-worth. Study 2 examined relations between ASP participation and development of concentration and emotion regulation skills in rural Latino grade-school youth. In this study, youth who regularly attended the ASP demonstrated significantly better concentration and regulation skills than those who did not regularly attend, if they exhibited preexisting concentration and regulation problems. Findings illustrate how ASPs with varying strategies, activities, and assessment tools can be evaluated in the interest of designing future large-scale investigations into ASPs and Latino positive youth development.     

Should goal-strivers think about “why” or “how” to strive? It depends on their skill level

The current studies attempted to increase individuals’ internalization of their own difficult or unpleasant goals, using either a low-level or a high-level writing intervention. Two writing studies showed that an appropriate match between level of goal-relevant skill (low versus high) and level of prompted goal-cognition (low versus high) enhances motivation. Those lower in initial skills were more likely to internalize their goals over time (Studies 1 and 2) and report greater goal expectancies (Study 2) if they wrote about the “how” of the goals, whereas those higher in initial skills were more likely to experience these positive outcomes by writing about the “why” of goals. This interaction pattern was found in both a short-term experimental study of health goals (Study 1) and in a 2 month longitudinal study of academic goals (Study 2). Results are discussed in the context of action identification theory and of self-regulation, which emphasize allocating attention to the right level of abstraction for optimal functioning.     

Hemispheric specialization for emotional word processing is a function of SSRI responsiveness

Vulnerability to depression and non-response to Selective Serotonin Reuptake Inhibitors (SSRIs) are associated with specific neurophysiological characteristics including greater right hemisphere (RH) relative to left hemisphere (LH) activity. The present study investigated the relationship between hemispheric specialization and processing of emotional words using a divided visual field paradigm administered to never-depressed and previously-depressed individuals, who were subdivided into SSRI responders and non-responders. SSRI responders and never-depressed participants were similar in their left hemispheric lateralization for evaluating emotional words. In contrast, SSRI non-responders showed a relative shift towards RH processing of negative words, and a strong bias toward negative evaluation of words presented to the RH. The results are discussed within the context of a biological-cognitive model of vulnerability to depression.     

Evaluation of Techniques to Promote Generalization with Basic Math Fact Skills

The purpose of the current study was to investigate the effect of three procedures designed to promote the generalization of fluent responding of 12 addition facts to 12 related subtraction facts. The first procedure was completed to determine whether increases in the number of digits correct per minute computed on addition facts would generalize to related subtraction facts. If students were fluent in the targeted addition problems and no generalization was detected, a second procedure was implemented where students completed a conceptual lesson. If no generalization was observed during this phase, a third procedure was implemented where students completed addition problems presented in a cloze format. Results failed to demonstrate generalized fluency gains across any of the procedures. Discussion focuses on future directions of generalization research to further our understanding of the conditions needed for generalization to occur.