Deceptive Signals Research Articles

The influence of postreliance detection on the deceptive efficacy of dishonest signals of intent: Understanding facial clues to deceit as the outcome of signaling tradeoffs

Evolutionary communication theory posits that signalers and receivers are in a coevolutionary arms race. Receivers attempt to predict the behavior of signalers, and signalers attempt to manipulate the behavior of receivers (often through the use of dishonest signals of intent). This has led to the perception that deceitful signalers prefer perfectly deceptive signals. However, it is often easy for receivers to determine that a signal of intent was dishonest after relying on it to their detriment. Even the best deceivers may then acquire a reputation for being dishonest. For instance, in Prisoner's Dilemma (PD)-like social situations, predictable defectors make better social partners than unpredictable defectors. When opportunities to engage in social interaction depend on one's reputation for predictability, those who are better at concealing their defecting intentions may suffer the most from the reputations they acquire. Deceivers then face a tradeoff between the short-term benefits of successful deception and the long-term costs to their reputations. A mathematical model is developed and it is shown that the tradeoff often favors signalers who produce imperfectly deceptive signals over perfectly honest or perfectly deceptive ones. Implications for understanding human facial expressions and sociopathy are drawn.

Deceptive signals of phase transitions in small magnetic clusters.

We present an analysis of the thermodynamic properties of small transition-metal clusters and show how the commonly used indicators of phase transitions such as peaks in the specific heat or magnetic susceptibility can lead to deceptive interpretations of the underlying physics. The analysis of the distribution of zeros of the canonical partition function in the whole complex temperature plane reveals the nature of the transition. We show that signals in the magnetic susceptibility at positive temperatures have their origin at zeros lying at negative temperatures.

Courtship role reversal and deceptive signals in the long-tailed dance fly, Rhamphomyia longicauda

We examined the function of secondary sexual characters in the role-reversed, lekking behaviour of female long-tailed dance flies, Rhamphomyia longicauda Loew (Empididae), to test the hypothesis that the degree of abdominal distention is an honest female signal about the state of egg development. Female Rhamphomyia cannot hunt for prey and they receive all of their protein from males by exchanging copulations for nuptial prey gifts. Females compete for male gifts within leks that are organized for a brief period each evening before dark. Before hovering within leks, females swallow air, inflating expandable pouches on the pleural margins of the abdomen. The result is a large saucer-like abdomen which is further exaggerated by wrapping scaled pro-, meso- and metathoracic legs along its pleural margins. Male preference for an enlarged abdomen was confirmed by suspending plastic models of varying size from monofilament lines and recording which models attracted the most males. There was a positive relationship between egg development and abdominal distention in a related species,R.sociabilis (Williston), which lacks inflatable abdominal pouches. Multiple regression showed that inR.longicauda , abdominal inflation completely masks the state of egg development. We conclude that femaleR.longicauda deceive mate-seeking males with the unreliable message that eggs are nearing maturation in order to obtain a protein meal in exchange for copulation. Males that fail to identify a female bearing mature eggs risk near-certain cuckoldry and an increased probability that the female will die before oviposition.

The Body and Face of Woman: One Ornament that Signals Quality?

Evidence has accumulated in recent years supporting the hypothesis that both facial and bodily physical attractiveness in humans are certifications of developmental and hormonal health. Such evidence indicates that physical attractiveness is an honest or Zahavian signal of phenotypic and genetic quality. The hypothesis that physical beauty connotes health was first proposed by Westermarck and was discussed later by Ellis and Symons. It has been suggested that facial attractiveness in women is a deceptive signal of youth, unrelated to phenotypic and genetic quality. This sensory-bias or super-stimulus hypothesis is not supported by this study of men’s ratings of the attractiveness of photographs of 92 nude women. Independent ratings of photographs of faces, fronts with faces covered, and backs of the same women are significantly, positively correlated. The correlation between the ratings of different photos implies that women’s faces and external bodies comprise a single ornament of honest mate value, apparently constructed during puberty by estrogen and also probably by developmental adaptations for symmetry. Thus, women’s physical attractiveness in face and body honestly signal hormonal and perhaps developmental health.

Survival cost of an intrasexually selected ornament in a damselfly

Ornaments could evolve as honest indicators of fighting ability, provided they have costs that make deceptive signalling unprofitable. I tested for such costs by manipulating the size of the intrasexually selected wing spots of male rubyspot damselflies (Hetaerina americana) and monitoring survival in the field. Males with enlarged spots had higher mortality rates than both unmanipulated and sham-manipulated controls. Natural wing spot size correlated positively with longevity, which suggests that higher quality males develop larger spots.

Skeptical responding in rhesus monkeys (Macaca mulatta)

Signalers that misinform sufficiently open may become devalued as sources of information; however, “skepticism” and any comparison involved in testing reliability entail a cost that involves delays and energy expenditure. Skepticism may be less costly though, if, as a rule, animals are not equally skeptical of the signals of all conspecifics. Animals with the ability to recognize individual conspecifics and to recall past encounters with them may have the capacity to restrict skepticism to subsets of animals that are most likely to benefit from deception. We played tape-recorded alarm calls of high- and low-ranking rhesus monkeys(Macaca mulatta) to their groups in a feeding context once daily over 8 consecutive days at the Yerkes Primate Center Field Station. Over the sequence of playbacks, response was greater to the calls of high-ranking monkeys, adult response patterns were different from those of juveniles, and for adults especially, decline in responsiveness was punctuated by partial resurgences of response. These differences may be the consequence of the adults’ more extensive histories of interaction with group members that, though generally reliable, vary with respect to the potential benefits of deceptive signaling.

Human breasts: evolutionary origins as a deceptive signal of need for provisioning and temporary infertility

Les poitrines des femmes se developpent pendant la grossesse et la lactation. Pendant cette periode qui profite le plus a l'enfant, les hommes sont des pourvoyeurs plus genereux pour les femmes ayant une forte poitrine. Les hommes dominateurs considerent cependant une forte poitrine comme non attirante sexuellement. Ce comportement permet a ces femmes d'etre librement courtisees par des hommes non-dominateurs. Le courtisage implique l'approvisionnement des femmes, ce qui ameliore le bien-etre de l'enfant. Ainsi les femmes a forte poitrine etaient mieux « entretenues ». Les femmes ayant des genes favorisant le depot de graisse dans leur poitrine avaient des descendants plus nombreux afin que de tels genes soient selectionnes. Chez les primates non-humains chez lesquels l'approvisionnement par le mâle n'etait pas important, les depots de graisse preferentiels n'apparaissaient pas car de tels depots ne pouvaient conduire a un meilleur approvisionnement

Signal detection games with power constraints

Formulates and solves maximin and minimax detection problems for signals with power constraints. These problems arise whenever it is necessary to distinguish between a genuine signal and a spurious one designed by an adversary with the principal goal of deceiving the detector. The spurious (or deceptive) signal is subject to certain constraints, such as limited power, which preclude it from replicating the genuine signal exactly. The detection problem is formulated as a zero-sum game involving two players: the detector designer and the signal designer. The payoff is the probability of error of the detector, which the detector designer tries to minimize and the deceptive signal designer to maximize. For this detection game, saddle point solutions-whenever possible-or otherwise maximin and minimax solutions are derived under three distinct constraints on the deceptive signal power; these distinct constraints involve lower bounds on (i) the signal amplitude, (ii) the time-averaged power, and (iii) the expected power. The cases of independent and identically distributed and correlated signals are considered.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

EXPERIMENTAL EVIDENCE FOR INTERSPECIFIC FEMALE MIMICRY IN SYMPATRIC FICEDULA FLYCATCHERS.

Interactions between closely related species in zones of overlap have received much attention in biological literature. Related species may have similar ecological requirements as well as sufficiently similar mate recognition systems for interbreeding to occur. One evolutionary consequence of such interactions may be character divergence of the species pair in sympatry (e.g., Brown and Wilson 1956). Characters that reduce interspecific competition (Arthur 1982; Grant 1986) or that increase assortative matings to reduce reproductive wastage (e.g., Butlin 1989) should be selected. Sympatric character modification may also be associated with the evolution of strategies that increase the competitive ability of a species. R0skaft et al. (1986) suggested a hypothesis of interspecific female mimicry for color divergence in male pied flycatchers (Ficedula hypoleuca) where they live in sympatry with collared flycatchers (F. albicollis). According to this hypothesis, male pied flycatchers may gain access to breeding territories among dominant, collared flycatchers through deceptive signaling of sex and species identity. Here we present an experimental test of the hypothesis of female mimicry. The pied and collared flycatchers are closely related species (Gelter 1989) of the family Muscicapidae whose distributions overlap in Central and Eastern Europe and on the islands of Gotland and Oland in the Baltic Sea (fig. 1). The plumage color of male pied flycatchers varies from a conspicuous black and white (color score 1) to a female like brown (color score 7; Drost

Deceptive or honest signalling of fighting ability? A test of alternative hypotheses for the function of changes in call dominant frequency by male cricket frogs

Previous data on intrasexual competition in Blanchard's cricket frog, Acris crepitans blanchardi, demonstrated that males assess the size of an opponent, an important component of fighting ability, based on the dominant frequency of an opponent's calls. Males of this species, however, often lower their dominant frequency in response to the calls of larger opponents, suggesting the conditional production of deceptive signals of size. In this study, playback experiments were used to test honest and deceptive signalling hypotheses for the function of changes in call dominant frequency. Calls that decreased in dominant frequency were more effective at repelling opponents than were calls that either increased, or did not change, in dominant frequency. A decrease in call dominant frequency therefore appears to convey an advantage in contests between male cricket frogs. During the period when males changed their dominant frequency, size became significantly less predictable from call dominant frequency. Furthermore, the extent to which males changed their dominant frequency was independent of size. Changes in call dominant frequency thus do not appear to function as honest signals of size. Because the extent to which males lowered their dominant frequency was positively correlated with their probability of attacking an opponent, and because animals producing deceptive signals should not attack opponents, changes in call dominant frequency do not appear to function as deceptive signals in size. Instead, changes in call dominant frequency appear to function as signals of size-independent fighting ability. The results presented suggest that male cricket frogs signal information about their size through initial call dominant frequency, and that they signal information about other aspects of their fighting ability through changes in call dominant frequency.

Withdrawal of life support in babies: deceptive signals.

Withdrawal of life support in babies: deceptive signals.

Cooperation Under Sexual Selection: Age-Graded Changes in a Lekking Bird

Long-tailed manakins, Chiroxiphia linearis, are birds with a lek mating system and male-male cooperation in courtship display. I studied male-male networks in a color-banded population in Monteverde, Costa Rica, from 1981 to 1987. Males displayed in scattered leks (75-300 m apart) comprising 3-15 males. Within each lek, an alpha and beta male, with strict relative dominance ranks, performed most of the courtship display. Of 50-60 active males per season, only 6-8 males were well-established alpha males in leks with consistent levels of dual-male displays (calls and dances). Demographic data suggest that males may be 8 yr of age or more before attaining beta status. Alpha tenure can last from two to at least four years. Alpha males were rarely or never seen in perch zones other than their primary perch zone (their area of dominance). Lower-ranking males maintained simultaneous affiliations with males in as many as six different zones. Each zone, therefore, acted as a hub in which males with different affiliations around the rim came into contact. Each of the six major perch zones shared at least one affiliate with each of the other zones, and roughly half the males in any particular zone were also known affiliates in one or more other zones. Marked changes occurred in male traits with increasing age and status: (1) significant declines in weight throughout the life span, without loss of dominance status; (2) a 4-yr delay in plumage maturation with distinct subdefinitive, transitional stages; (3) reduction in the number of perch zones with which older males maintained affiliations; and (4) increasing probability of copulatory success. The results are consistent with the hypothesis that subdefinitive plumages in this species serve primarily as accurate indicators of age, which in turn largely determines status, and that males queue for positions in an age-based dominance system. The results do not support the hypothesis that delayed plumage maturation involves mimicry or deceptive signaling by subdefinitive males (≤3 yr old) to high-ranking males (≥8 yr old). Of 85 males monitored from 1983 to 1986, copulations (N = 117) were distributed among 8 males. Four of these males accounted for over 90% of the copulations, with 67% accruing to one male. An index of the opportunity for sexual selection, to be used cautiously in interspecific comparisons, was estimated to range from 15.8 to 31.5 in four successive years. Direct benefits to cooperation by the beta male consisted of rare immediate copulations (N = 2) and eventual ascent to alpha status (N = 3). The high variance of mating success means few opportunities for success by younger males and should favor long-term strategies, such as cooperation and delayed plumage maturation, that enhance the prospects of future success.

Experiments on the Control of Deceptive Signals of Status in White-Crowned Sparrows

Abstract We showed previously that crown plumage brightness signals relative dominance ability in White-crowned Sparrows (Zonotrichia leucophrys gambelii). We now test the social-control hypothesis for the evolutionary stability of status signaling against invasion by individuals with brighter crowns than justified by their intrinsic dominance ability. "Cheating" immature females, with crowns painted to resemble bright adult males, and "control" immature females, with crowns painted a typical immature appearance or left unpainted, were released into two separate wild sparrow flocks and into two different captive groups that contained birds of all age and sex classes. In the field experiments, cheaters were more successful than controls in dominance interactions with other immatures; both groups were equally unsuccessful against adults. In the captivity experiments, cheaters generally dominated controls and were more successful than they in interactions with immature males and adult females but not with adult males. Cheaters did not receive more aggression from dominant individuals than did controls in any experiment, and in two experiments they received significantly less aggression. Thus, we found no socially mediated costs for sparrows with deceptive signals. Instead, we showed that immature females that cheat can benefit. The stability of the White-crowned Sparrow signaling system remains unexplained. We discuss the potential influence of predators on individual plumage differences and offer additional hypotheses for the control of deceptive signals.