Does parochial cooperation exist in childhood and adolescence? A meta-analysis

Although previous meta-analytic evidence supports the existence of parochialism in cooperation among adults, the extent to which children and adolescents are more willing to incur a personal cost to benefit ingroups, compared to outgroups, is not yet clear. We provide the first meta-analysis on the existence and magnitude of parochialism in cooperation among pre-adults. Based on 20 experimental economics studies (k = 69, N = 5268, age = 3–19, 12 countries, published 2008–2019), a multilevel meta-analytic model revealed a small overall effect size indicating that children and adolescents were more cooperative towards ingroups (d = 0.22, 95% CI [0.07, 0.38]). A series of single-moderator analyses tested for the following conditions: participant age and sex; game type ([mini-]dictator game, prisoner's dilemma, public goods dilemma, trust game, ultimatum game); outcome interdependence; membership manipulation (between- vs. within-subjects); group type (natural vs. experimental); reward type (monetary vs. non-monetary); and country of the participant. Parochial cooperation did not vary with participants' age. Parochialism was larger in non-interdependent (dictator-type) compared to interdependent (bargaining and social dilemma) games. There were no moderating effects of group type, membership manipulation or reward type. To provide more data on how parochialism develops, primary studies should report age ranges more precisely and use more restricted age groups.     

The Disappearing “Advantage of Abstract Examples in Learning Math”

When teaching a novel mathematical concept, should we present learners with abstract or concrete examples? In this experiment, we conduct a critical replication and extension of a well-known study that argued for the general advantage of abstract examples (Kaminski, Sloutsky, & Heckler, 2008a). We demonstrate that theoretically motivated yet minor modifications of the learning design put this argument in question. A key finding from this study is that participants who trained with improved concrete examples performed as well as, or better than, participants who trained with abstract examples. We argue that the previously reported “advantage of abstract examples” manifested not because abstract examples are advantageous in general, but because the concrete condition employed suboptimal examples.     

Objective and epistemic gradability: Is the new angle on the Knobe effect empirically grounded?

According to the New Angle, any explanation of the Knobe effect must be gradable and asymmetric. It has been argued that only Hindriks’ approach meets both criteria. First, we argue that Holton’s hypothesis also meets the criteria. Second, we show that the authors are not justified in taking the criteria to be empirically justified. We have failed to replicate the asymmetry result in two experiments. Moreover, gradability can be objective or epistemic. We show that the New Angle presupposes objective gradability. In our experiments, the patterns of responses to questions about epistemic and objective gradability are the same, irrespective of whether the feature is objectively gradable (e.g., blameworthiness) or not (e.g., intentionality). Our results thus question the extent to which the New Angle is empirically grounded. Moreover, they raise doubt whether the answers to questions about epistemic and objective gradability can be taken at face value at all.

Abbreviations: NRH - normative reasons hypothesis; NVH - norm violation hypothesis; DQ - degree question; DAQ - degree of agreement question     

Color opponency in synaesthetic experiences

Grapheme-color synaesthesia is a rare condition in which perception of a letter or a digit is associated with concurrent perception of a color. Synaesthetes report that these color experiences are vivid and realistic. We used a Stroop task to show that synaesthetically induced color, like real color, is processed in color-opponent channels (red-green or blue-yellow). Synaesthetic color produced maximal interference with the perception and naming of the real color of a grapheme if the real color was opponent to the synaesthetic color. Interference was reduced considerably if the synaesthetic and real colors engaged different color channels (e.g., synaesthetic blue and real red). No dependence on color opponency was found for semantic conflicts between shape and color (e.g., a blue lemon). Thus, the neural representation of synaesthetic colors closely resembles that of real colors. This suggests involvement of early stages of visual processing in color synaesthesia and explains the vivid and realistic nature of synaesthetic experiences.