Non-verbal behavior as courtship signals: the role of control and choice in selecting partners

In this work, we provide evidence based on direct observation of behavior in encounters of opposite-sexed strangers, that women initiate and “control” the outcome. In the first minute of these videotaped 10-min interactions, neither female “solicitation” behavior nor “negative” behavior is strongly related to professed interest in the man, while female “affirmative” behavior at this stage modulates male verbal output in later stages (4–10 min). Although the rate of female courtship-like behavior is significantly higher in the first minute, it is only in the fourth to tenth minute that the rate of female courtship-like behavior is correlated with professed female interest. We hypothesize that this serves as a strategic dynamic reflecting sexual asymmetry in parental investment and the potential cost of male deception to women. Ambiguous protean behavioral strategies veil individuals' intentions and make their future actions unpredictable. These behavioral strategies may result in men's overestimation of female sexual interest.     

Deception and hiding in captive lowland gorillas (Gorilla gorilla gorilla)

Deception and hiding are described for a group of captive lowland gorillas comprising two adult males, one female, and her infant. The males repeatedly interacted with the infant, and their interest was repeatedly thwarted by the mother. As in other social situations in which one animal controls access to an object desired by another, deceit was used to thwart the other's control. Either one or both males at times concealed their actions toward the infant, inhibited their attention to the infant, created a neutral image to get the infant, or interacted with the infant to tease the mother.     

A Preliminary Study of Microalgae in the Intertidal Zones of the Deception Island,Antarctica

his paper first presents a report on the composition and distribution of microalgae in the intertidal zones of the Deception Island, Antarctica. These microalgae samples were collected from six mud-sand flats stations on 21 January 1987. 179 taxa of microalgae belonging to Bacillariophyta (125 species, 25 varieties and 2 forma, 34 genera), Cyanophyta (18 species and 2 varieties, 6 genera), Pyrrophyta (6 species, 4 genera) and Chrysophyta (1 species 1 genus) were observed. The six dominant microalgae in each habitat are Fragilaria bongrainii, F. oceanica, F. striatula, F. islandica, Navicula antarctica and Synedra kerguelensis var. antarctica. Rhabdonema arcuatum, Cocconeis antiqua and Licmophora gracilis are abundant in station 4, 5 and 6. Oscillatoria spp., Lyngbya antarctica, Phormidium antarcticum and Nodularia spp. are also abundant in station 1, 2 and 3. The values of diversity indice for microalgae varied from 2. 85 to 6.86. The values of similarity indice in microalgae composition between biotopes ranged from 32 to 79 for pairs of stations. Microalgal species composition and quantitative distribution are depended on per cent contents of mud-sand and claysilt at different stations.     

Concealing facial evidence of mood: Perspective-taking in a captive gorilla?

A captive female lowland gorilla was observed repeatedly to hide or inhibit her playface by placing one or both hands over the face. When this behaviour was seen play usually did not follow immediately, even if other signals associated with play were simultaneously being made by the gorilla. By contrast, a playface predicted that play would follow within a few seconds; this difference was statistically reliable. Several levels of interpretation of the behaviour are possible: hiding the playface may have functioned as a form of deception, a meta-communication, or merely an attempt to suppress the playface. However, by any of these interpretations, the behaviour implies that the gorilla is aware of her spontaneous facial expressions and the consequences they entail. Among the great apes, manual suppression of a facial expression has previously been reported once for chimpanzees but never for gorillas.     

Self-deception as a mediator of cooperation and defection in varying social contexts described in the iterated prisoner''s dilemma

Deception and self-deception may be two related psychological capacities serving to enhance an individual's inclusive fitness. Self-deception has been defined as any psychological act in which one thought or belief is held at the expense of another. This study was designed to test the notion that we may deceive ourselves about our own intentions or the intentions of others in order to facilitate cooperation, if the cooperative behavior has the potential to improve fitness. We may also deceive ourselves in situations where we may need to compete with others, if not competing might represent a loss of fitness. The Self-Deceptio Questionnaire was administered to 80 women and 70 men to determine their levels of self-deception. A series of vignettes, conforming to the Prisoner's Dilemma game format, were administered in questionnaire material to measure participant's predispositions to cooperate or defect in three different contexts (family, mating, and neutral). Men predicted they would be less cooperative than women over all conditions, and participants anticipated cooperating more with kin than with non-kin. Moreover, participants who were high self-deceivers chose more cooperative responses in both family and mating contexts than those with low self-deception scores. Finally, the three-way interaction among sex, context, and level of self-deception suggested that the role of selfdeception in cooperation may vary according to the sex of the individual and the context.     

Assigned Versus Random,Countermeasure-Like Responses in the P300 Based Complex Trial Protocol for Detection of Deception: Task Demand Effects

We recently introduced an accurate and countermeasure resistant P300-based deception detection test called the complex trial protocol (Rosenfeld et al. in Psychophysiology 45(6):906–919, 2008). When subjects use countermeasures to all irrelevant items in the test, the probe P300 is increased rather than reduced (as it was in previous P300-based deception protocols), allowing detection of countermeasure users. The current experiment examines the role of task demand on the complex trial protocol by forcing the subject to make countermeasure-like response to stimuli. Subjects made either a simple random button response to both probe and irrelevant stimuli (experiment 1) or a more complex, assigned, button response to probe and irrelevant stimuli (experiment 2). We found that an increase in task demand reduced the effectiveness of the test. Using random responses we found a simple guilty hit rate of 11/12 with no false positives, but only a 4/11 hit rate for countermeasure-users. Using assigned responses we found a simple guilty hit rate of 8/15 with no false positives, and a 7/16 hit rate for countermeasure-users. We herein suggest that the high level of task demand associated with these countermeasure-like responses causes reduced hit rates.     

Algal communities of a geothermally heated lagoon on Deception Island (South Shetland Islands)

Kroner Lake, located at Deception Island (Maritime Antarctica), is a unique geothermally heated lagoon in Antarctica. It is declared as special site of scientific interest (SSSI) by Scientific Committee for Antarctic Research (SCAR) for its high biodiversity. A sharp environmental heterogeneity is registered in this lagoon, due to its connection to the sea in its southern margin, and to the input of warm freshwater in the northern one (because of hot springs). This study analyses the biodiversity and abundance of the algal communities (phytoplankton and benthic assemblages) and their relationship with environmental factors. In particular, strong spatial differences of both temperature and conductivity were recorded. The biological studies revealed that the phytoplankton (nanoplankton and microplankton) was dominated by marine diatom species, while the pico-sized fraction was composed by Cyanobacteria Synechococcus-like cells. The epipelon was mainly represented by chain and tubicolous diatoms, among which, Melosira nummuloides was one of the most abundant species. Filamentous Cyanobacteria were also frequently recorded in the algal mats. Kroner Lake is subject to a strong marine influence. Phytoplankton is absolutely dominated by marine diatoms. Spatial variations in temperature and conductivity recorded in the lagoon influence the distribution of the aquatic communities. The greater abundance of pico-sized cells coincided with the warmest site of the water body. Regarding the benthic community, the contribution of freshwater and brackish species is comparatively more important than for the phytoplankton, although the high contribution of marine-derived algae was also evident.     

Pollination biology of the Chilean endemic orchid Chloraea lamellata

Chloraea lamellata Lindl. is one of the 50 taxa of terrestrial orchids occurring in Chile. In this paper we report the breeding system, phenology and pollinator activity in a population of the species located in the Province of Valdivia, X Región, Chile (39°28 S). Chl. lamellata flowers from November to January, forming a lax spike with ca. 13 flowers. The floral life-span is 14 ± 4 days. The species is self-compatible. There was no statistical difference between the amount of seed produced after hand cross-pollination and hand self-pollination treatments. Neither direct autogamy nor agamospermy are involved in seed setting, thus pollinating agents are essential for the species' reproduction. Also, it has a high number of pollen grains (881733) and ovules (599833) per flower. The P/O ratio calculated is low (1.46). Probable pollinators belong to the orders Hymenoptera (Corynura chloris and Ruizantheda proxima) and Diptera (Sarcophagidae); these insects had a low visitation rate (0.00002 visits/spike/minute). The rate of pollination observed was low (28.6% flowers with pollinia deposited versus 71.3% flowers with pollinia removed). The reproductive features of Chl. lamellata suggest that the survival capability and long-term persistence of the species will be seriously threatened if the plant–pollinator interaction is disrupted.     

Mimicry for all modalities

Mimicry is a canonical example of adaptive signal design. In principle, what constitutes mimicry is independent of the taxonomic identity of the mimic, the ecological context in which it operates, and the sensory modality through which it is expressed. However, in practice the study of mimicry is inconsistent across research fields, with theoretical and empirical advances often failing to cross taxonomic and sensory divides. We propose a novel conceptual framework whereby mimicry evolves if a receiver perceives the similarity between a mimic and a model and as a result confers a selective benefit onto the mimic. Here, misidentification and/or deception are no longer formal requirements, and mimicry can evolve irrespective of the underlying proximate mechanisms. The centrality of receiver perception in this framework enables us to formally distinguish mimicry from perceptual exploitation and integrate mimicry and multicomponent signalling theory for the first time. In addition, it resolves inconsistencies in our understanding of the role of learning in mimicry evolution, and shows that imperfect mimicry is expected to be the norm. Mimicry remains a key model for understanding signal evolution and cognition, and we recommend the adoption of a unified approach to stimulate future interdisciplinary developments in this fascinating area of research.     

Identification of feigned ankle plantar and dorsiflexors weakness in normal subjects

Based on the limited ability of the human being to voluntarily control submaximal eccentric exertions, previous studies have indicated that isokinetic testing with a combined concentric–eccentric exercise protocol could effectively identify submaximal (feigned) effort in various muscle groups by showing an abnormally high eccentric to concentric ratio (ECR). The objective of this study was to determine the validity and accuracy of an ECR-based isokinetic test in identifying feigned ankle weakness. Thirty-eight normal subjects performed maximal and feigned efforts in an isokinetic concentric and eccentric ankle plantar- and dorsiflexion protocol with two different velocities, 30 and 120° s⁻¹. The isokinetic parameters ECR and the derivatives DEC (difference between ECR at high speed of motion and ECR at low speed of motion) and SEC (sum of ECR at high speed of motion plus the ratio between eccentric peak torque at high speed and concentric peak torque at low speed) were calculated. The ECR, DEC and SEC scores were significantly greater in feigned conditions for ankle plantarflexion, but not for dorsiflexion. Using optimal cutoff scores based on 99% tolerance intervals, it was disclosed that the most efficient parameter was the SEC, identifying 92% of the feigned efforts with 99% confidence, indicating that the ankle plantarflexors are less controllable in fast eccentric conditions than that in concentric conditions. The ECR-based parameters are valid for effectively identifying feigned plantarflexion effort with high accuracy, but do not allow the detection of feigned dorsiflexion weakness.