The Effect of Perceived Role Suitability on Prestige, Dominance, Performance, and Communication.

The pursuit of social rank is pervasive across societies and cultures. Previous studies have identified two distinct avenues for attaining social rank: prestige and dominance. While prestige (communication of skill/ability) and dominance (communication of superiority) are crucial to interpersonal interactions, it is unclear how people communicate prestige or dominance and how such communication affects team performance. To investigate these ideas, 206 individuals participated in a cooperative dyadic building task. A computer randomly assigned dyad members to one of two roles—builder (who handled and placed model pieces) and instructor (who directed the builder\u27s actions). Additionally, using a false feedback paradigm, a computer informed some participants they would perform better in either the builder or instructor role, regardless of their actual assigned role, to see whether perceived role aptitude affected prestige/dominance cues. Thus, the design included two factors: role (builder/instructor) and feedback type (matched with role, mismatched with role). During the task, participants worked together to construct a LEGO model, which was then scored for completion/correctness. Building sessions were video recorded for offline analysis. Data analysis showed the manipulated role feedback did not change partner-ratings of dominance or prestige, suggesting these interpersonal styles may function similarly to stable personality traits and are not dependent on perceived ability or role aptitude. Moreover, we found no evidence that partner-rated dominance or prestige communication affected how much of the model the group completed. However, the results show dominance had an effect on the number of mistakes made in the model in that mistakes were fewest when one partner was high in dominance and the other was low. Discussion focuses on how these variables relate to performance ability and interpersonal processes

Beyond Rank Attainment: Examining the Nature and Function of Dominance and Prestige in Teams

Social hierarchies are fundamental to human societies, shaping group dynamics and outcomes. Ongoing debates attempt to understand their functional and dysfunctional consequences. While the conflict account of hierarchy emphasizes the potentially detrimental conflict-inducing effects of hierarchies, the functionalist account proposes that hierarchies create contexts conducive to coordination. This study investigates if team-level dominance and prestige processes might account for these diverging consequences of hierarchy with dominance fueling conflict-prone environments and prestige nurturing coordination processes. Additionally, it examines whether the inherently competitive nature of team-level dominance yields more favorable outcomes in highly competitive, zero-sum, contexts. Across two studies, I investigated the nature and consequences of dominance and prestige processes on team functioning employing novel methodologies and conceptualizations to shed light on their mechanisms. Crucially, this research investigates dominance and prestige processes at the team-level, avoiding the limitations of individual-level perspectives. The research goes beyond mean-level investigations by also considering the influence of differentiation within teams in dominance and prestige alongside fluctuations in team-level dominance and prestige over time. Study 1 investigated the dynamics of team dominance and prestige within work teams by utilizing three years of longitudinal data situated within an ecologically valid context. Results demonstrated that group dominance positively related to conflict measures, highlighting its detrimental influences. Conversely, prestige was positively related to beneficial team dynamics including team potency and coordination. Furthermore, dominance and prestige differentiation had both positive and negative influences. Study 2 explored these relationships in a more controlled laboratory setting using distinct methodologies, types of participants, and team contexts. Additionally, I investigated if zero-sum contexts moderated the relationships dominance had with team functioning variables. The results from Study 2 suggested that dominance was the primary driver of team conflict, whereas prestige was the primary driver of team potency. However, prestige’s beneficial influence on coordination and conflict measures only manifested in the more competitive context. This suggests that something in more competitive environments might activate the beneficial influence of prestige. These findings provide insights into the nature and interplay between dominance, prestige, and team functioning. This research validates the group-centered approach and goes beyond solely relying on mean-level conceptualizations

Mapping the Traits Desired in Followers and Leaders onto Fundamental Dimensions of Social Evaluation

We applied the social evaluation framework to investigate the traits desired in an “ideal” follower, which were compared to the traits desired in an “ideal” leader. Across three studies and five samples, both differences and similarities in role-specific preferences mapped onto the Vertical-Horizontal dimensions of the social evaluation framework in ways that aligned with the demands of each role. Traits higher on the Horizontal-morality facet (e.g., cooperative, dutiful) and lower on the Vertical-assertiveness facet (e.g., confident, ambitious) differentiated ideal follower preferences from ideal leader preferences. Focusing on the traits most strongly desired in relation to each role, traits that supported social coordination and collective goal attainment (i.e., work ethic, cooperativeness) were prioritized in relation to ideal followers, whereas intelligence was prioritized for ideal leaders. Trustworthiness was equally valued across both roles. Moreover, we differentiated between necessary and luxury traits by adjusting the budget individuals could allocate towards the desired traits. Investments in necessary versus luxury traits further supported the social evaluation framework and highlighted the need to account for the facet-level distinctions within the Vertical (assertiveness, ability) and Horizontal (morality, friendliness) dimensions. Further, these findings were found to be robust across manipulations (e.g., the target’s gender and hierarchical level)

The distance to Hydra and Centaurus from surface brightness fluctuations: Consequences for the Great Attractor model

We present I-band Surface Brightness Fluctuations (SBF) measurements for 16 early type galaxies (3 giants, 13 dwarfs) in the central region of the Hydra cluster, based on deep photometric data in 7 fields obtained with VLT FORS1. From the SBF-distances to the galaxies in our sample we estimate the distance of the Hydra cluster to be 41.2 +/- 1.4 Mpc ((m-M)=33.07 +/- 0.07 mag). Based on an improved correction for fluctuations from undetected point sources, we revise the SBF-distance to the Centaurus cluster from Mieske & Hilker (2003) upwards by 10% to 45.3 +/- 2.0 Mpc ((m-M)=33.28 +/- 0.09 mag). The relative distance modulus of the two clusters then is (m-M)_Cen - (m-M)_Hyd = 0.21 +/- 0.11 mag. With H_0=72 +/- 4 km/s/Mpc, we estimate a positive peculiar velocity of 1225 +/- 235 km/s for Hydra and 210 +/- 295 km/s for the Cen30 component of Centaurus. Allowing for a thermal velocity dispersion of 200 km/s, this rules out a common peculiar flow velocity for both clusters at 98% confidence. We find that the 9*10^{15} M_{sun} ``Great Attractor'' from the flow study of Tonry et al. (2000) at a distance of ~45 Mpc can explain the observed peculiar velocities if shifted about 15 degrees towards the Hydra cluster position. Our results are inconsistent at 94% confidence with a scenario where the Centaurus cluster is identical to the Great Attractor. In order to better restrict partially degenerate Great Attractor parameters like its mass and distance, a recalculation of the local flow model with updated distance information over a larger area than covered by us would be needed.Comment: 18 pages, 10 Figures, accepted for publication in A&

Distances from Surface Brightness Fluctuations

The practice of measuring galaxy distances from their spatial fluctuations in surface brightness is now a decade old. While several past articles have included some review material, this is the first intended as a comprehensive review of the surface brightness fluctuation (SBF) method. The method is conceptually quite simple, the basic idea being that nearby (but unresolved) star clusters and galaxies appear "bumpy", while more distant ones appear smooth. This is quantified via a measurement of the amplitude of the Poisson fluctuations in the number of unresolved stars encompassed by a CCD pixel (usually in an image of an elliptical galaxy). Here, we describe the technical details and difficulties involved in making SBF measurements, discuss theoretical and empirical calibrations of the method, and review the numerous applications of the method from the ground and space, in the optical and near-infrared. We include discussions of stellar population effects and the "universality" of the SBF standard candle. A final section considers the future of the method.Comment: Invited review article to appear in: `Post-Hipparcos Cosmic Candles', A. Heck & F. Caputo (Eds), Kluwer Academic Publ., Dordrecht, in press. 22 pages, including 3 postscript figures; uses Kluwer's crckapb.sty LaTex macro file, enclose

Frequency and properties of bars in cluster and field galaxies at intermediate redshifts

We present a study of large-scale bars in field and cluster environments out to redshifts of ~0.8 using a final sample of 945 moderately inclined disk galaxies drawn from the EDisCS project. We characterize bars and their host galaxies and look for relations between the presence of a bar and the properties of the underlying disk. We investigate whether the fraction and properties of bars in clusters are different from their counterparts in the field. The total optical bar fraction in the redshift range z=0.4-0.8 (median z=0.60), averaged over the entire sample, is 25% (20% for strong bars). For the cluster and field subsamples, we measure bar fractions of 24% and 29%, respectively. We find that bars in clusters are on average longer than in the field and preferentially found close to the cluster center, where the bar fraction is somewhat higher (~31%) than at larger distances (~18%). These findings however rely on a relatively small subsample and might be affected by small number statistics. In agreement with local studies, we find that disk-dominated galaxies have a higher optical bar fraction (~45%) than bulge-dominated galaxies (~15%). This result is based on Hubble types and effective radii and does not change with redshift. The latter finding implies that bar formation or dissolution is strongly connected to the emergence of the morphological structure of a disk and is typically accompanied by a transition in the Hubble type. (abridged)Comment: 17 pages, accepted for publication in A&

Distance to the Centaurus cluster and its subcomponents from surface brightness fluctuations

We present I-band Surface Brightness Fluctuations (SBF) measurements for 15 early type galaxies (3 giants, 12 dwarfs) in the central region of the Centaurus cluster, based on VLT FORS1 imaging data. From the SBF-distances to our sample galaxies we determine the distance of the Centaurus cluster to be 41.3 +/- 2.1 Mpc (33.08 +/- 0.11 mag), about the same distance as of the ``Great Attractor''. We find a distance difference of 0.27 +/- 0.34 mag between the two subcomponents Cen30 and Cen45, ruling out that both components are separated by their Hubble flow distance. A distance difference of 0.48 +/- 0.21 mag is found between the central galaxies NGC 4696 (Cen30) and NGC 4709 (Cen45) of both components, supported by the different turn-over magnitudes of their respective globular cluster systems. This suggests that Cen45 is falling into but has not yet reached Cen30, supporting the idea of a large scale filament along the line of sight towards Centaurus (Churazov et al. 1999). H_0=83.0 +/- 8.3 km/s/Mpc is obtained for our Cen30 sample. This value corresponds to a much smaller Hubble flow distortion in the direction of Centaurus than determined by Tonry et al. (2000), implying that the GA mass estimate by Tonry et al. may be too high and/or that the Centaurus cluster falls into the GA almost perpendicularly to the line of sight. As our mean single measurement error is very close to the measured distance scatter of the investigated galaxies, we can only derive an upper limit of +/- 10 Mpc radial extension for the Centaurus cluster. No evidence for an infall pattern into the Great Attractor is found within the uncertainties for the 11 galaxies with measured redshift.Comment: 16 pages, 10 figures, accepted for publication in A&

Resolved Images of Large Cavities in Protoplanetary Transition Disks

Circumstellar disks are thought to experience a rapid "transition" phase in their evolution that can have a considerable impact on the formation and early development of planetary systems. We present new and archival high angular resolution (0.3" = 40-75 AU) Submillimeter Array (SMA) observations of the 880 micron dust continuum emission from 12 such transition disks in nearby star-forming regions. In each case, we directly resolve a dust-depleted disk cavity around the central star. Using radiative transfer calculations, we interpret these dust disk structures in a homogeneous, parametric model framework by reproducing their SMA visibilities and SEDs. The cavities in these disks are large (R_cav = 15-73 AU) and substantially depleted of small (~um-sized) dust grains, although their mass contents are still uncertain. The structures of the remnant material at larger radii are comparable to normal disks. We demonstrate that these large cavities are common among the millimeter-bright disk population, comprising at least 20% of the disks in the bright half of the millimeter luminosity (disk mass) distribution. Utilizing these results, we assess some of the physical mechanisms proposed to account for transition disk structures. As has been shown before, photoevaporation models do not produce the large cavity sizes, accretion rates, and disk masses representative of this sample. It would be difficult to achieve a sufficient decrease of the dust optical depths in these cavities by particle growth alone: substantial growth (to meter sizes or beyond) must occur in large (tens of AU) regions of low turbulence without also producing an abundance of small particles. Given those challenges, we suggest instead that the observations are most commensurate with dynamical clearing due to tidal interactions with low-mass companions --young brown dwarfs or giant planets on long-period orbits.Comment: ApJ, in pres

The orbital velocity anisotropy of cluster galaxies: evolution

In nearby clusters early-type galaxies follow isotropic orbits, while the orbits of late-type galaxies are characterized by slightly radial anisotropy. Little is known about the orbits of the different populations of cluster galaxies at redshift above z~0.3. Here we investigate the redshift evolution of the orbits of cluster galaxies using two samples of galaxy clusters spanning similar (evolutionary corrected) mass ranges at different redshifts. The low-redshift (z~0.0-0.1) sample is extracted from the ENACS catalog and the high-redshift (z~0.4-0.8) sample is mostly made of clusters from the EDisCS. For each of these samples, we solve the Jeans equation for hydrostatic equilibrium separately for two cluster galaxy populations, characterized by the presence and, respectively, absence of emission-lines in their spectra ('ELGs' and 'nELGs' hereafter). Using two tracers of the gravitational potential allows to partially break the well known mass-velocity anisotropy degeneracy. We find no significant evolution for the orbits of ELGs. On the other hand the orbits of nELGs do evolve, from radial to isotropic with time. We speculate that this evolution may be driven by the secular mass growth of galaxy clusters during their fast accretion phase. The mass density profiles of the clusters are well fit by NFW models both in the low-z and in the high-z samples. The best-fit NFW concentrations and their redshift evolution are in agreement with the predictions of Lambda CDM cosmological simulations. The evolution of the number density profile of nELGs is opposite to that of the mass density profile, becoming less concentrated with time, probably a result of the transformation of ELGs into nELGs [abridged].Comment: 9 pages, 5 figures. Astr. Ap., 501, 419. Corrected typos in abstract wrt previous versio

The anatomy of the NGC 5044 group - I. Group membership and dynamics

We use a combination of new AAOmega multi-object wide-field spectroscopic observations and literature data to define 111 spectroscopically confirmed members of the massive NGC 5044 group with M_B <= -13.5 mag, providing a three-fold increase in group members over previous analyses of this group. We find the group to have a dynamical mass of 9.2 x 10^13 solar masses, placing it on the border between rich groups and poor clusters. However, comparison to the L_x-sigma and L_x-mass relations shows it more closely follows cluster scaling relations. Using a combination of crossing time, X-ray contours and line-of-sight velocity profile we are able to preclude growth of the NGC 5044 group via major sub-group mergers within the last ~1 Gyr. While the majority of dynamical indicators for the group suggest it is virialised, we find evidence for a small, dynamically distinct sub-group at 1.4 Mpc from the group centre, suggesting that the NGC 5044 group is the dominant structure in its local environment, and is currently accreting smaller groups.Comment: 18 pages, 17 figures, accepted by MNRAS. Updated to match proof versio