Food, “Culture,” and Sociality in Drosophila

International audiencewith naïve " observers " with two fresh, flavored media (without quinine). In the critical test phase, demonstrators and observers were exposed separately to the two flavored media. Social transmission occurred if the oviposition choices of observers mirrored that of demonstrators. Using this methodology, Battesti et al. (2012) first showed that observer flies relied heavily on social information and acquired oviposition preferences from demonstrators , even if they had the opportunity to sample the two equally suitable media during the transmission phase, thus confirming previous observations in this species (Sarin and Dukas, 2009). The authors next investigated the mechanisms of social transmission and showed that social learning did not occur when observers were exposed to social cues only (freshly laid eggs and aggregation phero-mone) on one of the two media. Social transmission, however, always occurred when observers interacted directly with demonstrators, even if the media were unflavored. Although the precise mechanism of social learning remains an open A commentary on Spread of social information and dynamics of social transmission within Drosophila groups by Battesti Communication with and learning from others are key features of social life. We humans rely extensively on the advice of others before making important decisions. Social insects too, such as bees and ants, use social information to learn about foraging opportunities and engage in collective tasks (Dussutour and Simpson, 2009; Seeley et al., 2012). Growing interest into the learning abilities of small-brained animals has revealed that social learning in insects is more diverse and more common than previously thought (Leadbeater and Chittka, 2007), thus offering new opportunities for comparative analyses of the role of cognition in the regulation of social behavior across a rich spectrum of social forms. Recently, the fruit fly Drosophila melanogaster (Figure 1A) has emerged as a key species for studying social learning in simple insect groups (Mery et al., 2009; Sarin and Dukas, 2009). Flies aggregate on food resources, where they feed, reproduce, lay eggs, and glean information from each other. Writing in a recent issue of Current Biology, Battesti et al. (2012) present evidence that Drosophila females not only use social information to select oviposition sub-strates, but also that these socially acquired preferences can propagate and stabilize within groups, a phenomenon resembling cultural transmission of knowledge in vertebrates (Laland, 2008). The authors used a three-step experimental paradigm (Figure 1B). A group of flies was first trained to associate an aversive gustatory cue (quinine) with an artificial flavor (banana or strawberry) characterizing one of two standard ovipo-sition media (agar and sugar). These conditioned " demonstrators " were then caged question, presumably, it can be explained by relatively simple associative learning processes occurring during physical contacts between observer and demonstrator flies through the perception of the olfactory cues (banana or strawberry flavors) carried by the demonstrators. Such mechanism, for instance, underpins social transmission of food preferences in rats (Galef et al., 1985). In a third set of experiments, Battesti et al. (2012) have gone a step further into the understanding of how flies balance their use of social and personal information. By exposing observers to the two flavored media at the different phases of the experimental paradigm they demonstrated that the socially acquired preference vanished if observers were allowed to acquire personal information after the transmission phase. Considering the short lifespan of Drosophila (Lee et al., 2008), rapidly adopting the behavior of the majority may provide naïve flies with cues to choices that are locally adaptive and prevent costly trial and error. However, if information about resources is abundant and not costly t

Claims and confounds in economic experiments

We present a distinctiveness, relevance and plausibility (DRP) method for systematically evaluating potential experimental confounds. A claim is a statement being inferred on the basis of experimental data analysis. A potential confound is a statement providing a prima facie reason why the claim is not justified (other than internal weakness). In evaluating whether a potential confound is problematic, we can start by asking whether the potential confound is distinctive from the claim; we can then ask whether it is relevant for the claim; and we can conclude by asking whether it is plausible in the light of the evidence

The role of decision confidence in advice-taking and trust formation

In a world where ideas flow freely between people across multiple platforms, we often find ourselves relying on others' information without an objective standard to judge whether those opinions are accurate. The present study tests an agreement-in-confidence hypothesis of advice perception, which holds that internal metacognitive evaluations of decision confidence play an important functional role in the perception and use of social information, such as peers' advice. We propose that confidence can be used, computationally, to estimate advisors' trustworthiness and advice reliability. Specifically, these processes are hypothesized to be particularly important in situations where objective feedback is absent or difficult to acquire. Here, we use a judge-advisor system paradigm to precisely manipulate the profiles of virtual advisors whose opinions are provided to participants performing a perceptual decision making task. We find that when advisors' and participants' judgments are independent, people are able to discriminate subtle advice features, like confidence calibration, whether or not objective feedback is available. However, when observers' judgments (and judgment errors) are correlated - as is the case in many social contexts - predictable distortions can be observed between feedback and feedback-free scenarios. A simple model of advice reliability estimation, endowed with metacognitive insight, is able to explain key patterns of results observed in the human data. We use agent-based modeling to explore implications of these individual-level decision strategies for network-level patterns of trust and belief formation

Organizational Behavior: Production of Knowledge for Action in the World of Practice

If a policy is a solution, “actionable knowledge is the actual behavior required to implement the solution

Learning and Visceral Temptation in Dynamic Savings Experiments

In models of optimal savings with income uncertainty and habit formation, people should save early to create a buffer stock, to cushion bad income draws and limit the negative internality from habit formation. In experiments in this setting, people save too little initially, but learn to save optimally within four repeated lifecycles, or 1-2 lifecycles with “social learning.” Using beverage rewards (cola) to create visceral temptation, thirsty subjects who consume immediately overspend compared to subjects who only drink after time delay. The relative overspending of immediate-consumption subjects is consistent with hyperbolic discounting and dual-self models. Estimates of the present-bias choices are β=0.6-0.7, which are consistent with other studies (albeit over different time horizons)

Doing pedagogical research in engineering

This is a book

The effects of an experimental programme to support students’ autonomy on the overt behaviours of physical education teachers

Although the benefits of autonomy supportive behaviours are now well established in the literature, very few studies have attempted to train teachers to offer a greater autonomy support to their students. In fact, none of these studies has been carried out in physical education (PE). The purpose of this study is to test the effects of an autonomy-supportive training on overt behaviours of teaching among PE teachers. The experimental group included two PE teachers who were first educated on the benefits of an autonomy supportive style and then followed an individualised guidance programme during the 8 lessons of a teaching cycle. Their behaviours were observed and rated along 3 categories (i.e., autonomy supportive, neutral and controlling) and were subsequently compared to those of three teachers who formed the control condition. The results showed that teachers in the experimental group used more autonomy supportive and neutral behaviours than those in the control group, but no difference emerged in relation to controlling behaviours. We discuss the implications for schools of our findings