Worth the wait: Children trade off delay and reward in self‐ and other‐benefiting decisions

Human prosocial behaviors are supported by early‐emerging psychological processes that detect and fulfill the needs of others. However, little is known about the mechanisms that enable children to deliver benefits to others at costs to the self, which requires weighing other‐regarding and self‐serving preferences. We used an intertemporal choice paradigm to systematically study and compare these behaviors in 5‐year‐old children. Our results show that other‐benefiting and self‐benefiting behavior share a common decision‐making process that integrates delay and reward. Specifically, we found that children sought to minimize delay and maximize reward, and traded off delays against rewards, regardless of whether these rewards were for the children themselves or another child. However, we found that children were more willing to invest their time to benefit themselves than someone else. Together, these findings show that from childhood, other‐ and self‐serving decisions are supported by a general mechanism that flexibly integrates information about the magnitude of rewards, and the opportunity costs of pursuing them. A video abstract of this article can be viewed at: https://youtu.be/r8S0DGe7f8QWe investigated the representations and computations that support decision‐making in children through use of an intertemporal choice paradigm. Our results suggest that self‐ and other‐benefitting decisions in childhood are supported by tradeoffs between variables like the magnitude of rewards and the opportunity costs of pursuing them.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146808/1/desc12702_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146808/2/desc12702.pd

I like what I know: How recognition-based decisions can structure the environment

Abstract. Cognitive mechanisms are shaped by evolution to match their environments. But through their use, these mechanisms exert a shaping force on their surroundings as well. Here we explore this cognition-environment interaction by looking at how using a very simple cognitive mechanism, the recognition heuristic for making choices, can result in some objects in the world being much more often recognized and “talked about ” than others. An agent-based simulation is used to show what behavioral factors affect the emergence of this environmental structure.

Equações de predição para estimar valores da energia metabolizável de alimentos concentrados energéticos para aves utilizando meta-análise

Obtiveram-se equações de predição dos valores de energia metabolizável aparente corrigida (EMAn) para alimentos energéticos mais utilizados nas dietas de frangos de corte por meio do princípio da meta-análise. Foi realizada uma revisão bibliográfica de estudos realizados no Brasil para catalogar informações sobre valores de EMAn e composição química dos alimentos (PB; EE; MM; FB, FDN e FDA). Também foram considerados os efeitos de sexo, macho, fêmea e mistos de idade (primeira e segunda semanas, terceira e quarta semanas, quinta e sexta semanas e acima de seis semanas ou indefinido), e da metodologia empregada no metabolismo (coleta total de excretas ou alimentação forçada + coleta total de excretas), formando um esquema fatorial (3x4x2). Adotou-se o procedimento de Stepwise para estudar a associação entre as variáveis, incluindo-as na equação em função de suas importâncias, e o Proc Reg do SAS para ajustar o modelo de regressão linear múltipla. As melhores equações para estimar a EMAn dos alimentos foram EMAn = 4371,18 - 26,48PB + 30,65EE - 126,93MM - 52,26FB - 25,14FDN + 24,40FDA (R²=0,81) e EMAn = 4205,23 + 30,58EE - 130,35MM - 58,29FB - 28,31FDN + 16,71FDA (R²=0,81). As variáveis FDN e FDA foram importantes nas equações ao influenciarem os valores energéticos dos alimentos

Fish assemblages in temporary ponds adjacent to 'terra-firme' streams in Central Amazonia

1. The effect of habitat structural features and physicochemical characteristics of the water on the composition and richness of fish assemblages in temporary ponds near streams were examined at three spatial scales: among ponds, among streams and between drainage basins, in a 'terra-firme' (not subject to long-term flooding) forest reserve in Central Amazonia. 2. The fish assemblage in temporary ponds was composed of subsets of 18 small-bodied species widely distributed in the reserve. The assemblages had a nested subset structure, where smaller ponds contained subgroups of the species found in larger ponds. 3. Species composition and richness in temporary ponds were similar between drainage basins, although the fish assemblages in streams differed between basins. 4. Fish assemblage structure was influenced by local factors related to habitat structure, such as pond area and depth, canopy cover and hydroperiod. Physicochemical characteristics of the water in the ponds were similar between drainage basins and had little detectable effect on the structure of pond fish assemblages. 5. No correspondence was found between the composition, richness or abundance of fishes in the ponds and in stretches of the streams adjacent to the ponds. Therefore, it is not possible to predict the composition of these temporary pond fish assemblages from the fish assemblages found in adjacent streams. © 2006 Blackwell Publishing Ltd