Benthic biomass size spectra in shelf and deep-sea sediments

The biomass distributions of marine benthic metazoans (meio- to macro-fauna, 1 ?g–32 mg wet weight) across three contrasting sites were investigated to test the hypothesis that allometry can consistently explain observed trends in biomass spectra. Biomass (and abundance) size spectra were determined from observations made at the Faroe–Shetland Channel (FSC) in the Northeast Atlantic (water depth 1600 m), the Fladen Ground (FG) in the North Sea (150 m), and the hypoxic Oman Margin (OM) in the Arabian Sea (500 m). Observed biomass increased with body size as a power law at FG (scaling exponent, b = 0.16) and FSC (b = 0.32), but less convincingly at OM (b = 0.12 but not significantly different from 0). A simple model was constructed to represent the same 16 metazoan size classes used for the observed spectra, all reliant on a common detrital food pool, and allowing the three key processes of ingestion, respiration and mortality to scale with body size. A micro-genetic algorithm was used to fit the model to observations at the sites. The model accurately reproduces the observed scaling without needing to include the effects of local influences such as hypoxia. Our results suggest that the size-scaling of mortality and ingestion are dominant factors determining the distribution of biomass across the meio- to macrofaunal size range in contrasting marine sediment communities. Both the observations and the model results are broadly in agreement with the "metabolic theory of ecology" in predicting a quarter power scaling of biomass across geometric body size classes

Building bonds: A pre-registered secondary data analysis examining linear and curvilinear relations between socio-economic status and communal attitudes

A large body of research points to differences in the communal orientation of people from a lower and higher socio-economic status (SES) background. However, direct evidence for differences in communal attitudes remains scant. In this pre-registered report, we test the hypothesis that SES impacts the incentive value of cues associated with bonding and social relations, thereby fostering differences in implicit and explicit communal attitudes. We further speculate that for people at the low end of the SES spectrum, the prevalence of discrimination, exclusion, and conflict means that relationships may have less of an incentive value. Thus, we hypothesise that the association between SES and communal attitudes follows a curvilinear trajectory and peaks at medium levels of SES. Testing these predictions in a dataset derived from the Attitudes, Identities, and Individual Differences (AIID) Study (Hussey, Hughes, & Nosek, 2018), we found no evidence supporting a linear or a curvilinear association between SES and communal attitudes. Instead, implicit and explicit communal attitudes did not vary across the SES spectrum. We discuss the implications of these findings and avenues for future research