Sexual and aggressive play fighting of sibling Richardson’s ground squirrels

Play fighting in many species of squirrels can involve sexual play and aggressive play, both of which can lead to wrestling which appears superficially similar. Such convergence can make scoring of the relative frequencies of these two types of play difficult and can lead to the mistaken conclusion that they grade into one another. In this study, both staged laboratory encounters between sibling pairs and spontaneous encounters between siblings in free‐living litters of Richardson’s ground squirrels (Spermophilus richardsonii) were videotaped. Frame‐by‐frame analyses using the Eshkol‐Wachman Movement Notation were employed to record the correlated movements of attack and defense by the partners and to reveal the body areas targeted during each play bout. Whereas sexual play was organized around access to the rump, aggressive play was organized around the shoulders. Although in most cases the defender’s tactics blocked access to the respective target, when contact did occur, it involved mounting in sexual play and nosing or biting in aggressive play. Eighty‐six percent of play fights could be unambiguously categorized as either sexual or aggressive play. Of these, the majority (?80%) involved sexual play. The sex of the participants did not affect the frequency of aggressive play, but in sexual play, males initiated more attacks than females. Once initiated, each form of play fighting remained distinct—if a bout began as sexual play, it would end as sexual play. Furthermore, a counterattack following sexual play was significantly more likely to be sexual than aggressive, and vice versa for counterattacks following aggressive play. Therefore, all the evidence suggested that the two forms of play fighting were not intermixed in Richardson’s ground squirrels. Aggr. Behav. 27:323–337, 2001. © 2001 Wiley‐Liss, Inc.     

Targets and tactics of agonistic and precopulatory behavior in montane and prairie voles: Their relationship to juvenile play-fighting

Play-fighting by juvenile montane and prairie voles involves attack and defense of the head, neck and shoulders. Since during play animals typically borrow behavior patterns from other functional contexts, two adult behavioral contexts were compared to juvenile play-fighting. These were serious fighting and sexual encounters. During serious fighting in a resident-intruder paradigm, most bites are directed at the rump and lower flanks. During sexual encounters, especially in precopulatory behavior, the head, neck and shoulders are gently contacted. Therefore, play-fighting by juveniles would appear to involve attack and defense of areas of the body contacted in adult precopulatory behavior, not adult fighting. Furthermore, the species-specific differences in juvenile play-fighting were also found to be matched by species-specific differences in precopulatory behavior. In both playful and precopulatory encounters, montane voles contacted the head and used upright defensive behaviors more often than prairie voles. In contrast, prairie voles made mutual contact more often and were more likely to rotate to supine in defense of contact to the nape and head. These findings support our hypothesis that juvenile play-fighting in muroid rodents involves the precocial expression of precopulatory, not agonistic behavior.     

Beyond the aggregate score: Using multilevel modeling to examine trajectories of laboratory-measured aggression

Aggression is often measured in the laboratory as an iterative “tit-for-tat” sequence, in which two aggressors repeatedly inflict retaliatory harm upon each other. Aggression researchers typically quantify aggression by aggregating across participants’ aggressive behavior on such iterative encounters. However, this “aggregate approach” cannot capture trajectories of aggression across the iterative encounters and needlessly eliminates rich information in the form of within-participant variability. As an alternative approach, I used multilevel modeling (MLM) to examine the slope of aggression across the 25-trial Taylor Aggression Paradigm as a function of trait physical aggression and experimental provocation. Across two preregistered studies (combined N = 392), participants exhibited a modest decline in aggression. This decline reflected a reciprocal strategy, in which participants responded to an initially-provocative opponent with greater aggression that then decreased over time to match their opponent's declining levels of aggression. Against predictions, trait physical aggression and experimental provocation did not affect participants’ overall trajectories of aggression. Yet, exploratory analyses suggested that the participants’ tendency to reciprocate their opponent's aggression with more aggression was greater at higher levels of trait physical aggression and attenuated among participants who had already been experimentally provoked by their opponent. These findings (a) illustrate several advantages of an MLM approach as compared with an aggregate approach to iterative laboratory aggression paradigms; (b) demonstrate that the magnifying effects of trait aggression and experimental provocation on laboratory aggression are stable over brief time-frames; and (c) suggest that modeling the opponent's behavior on such tasks reveals important information.     

Targets of attack and defense in play-fighting of the Djungarian hamster Phodopus campbelli: Links to fighting and sex

Analysis of the body targets attacked and defended during play-fighting by juvenile Djungarian hamsters Phodopus campbelli revealed that about 70% of all attacks were directed at the mouth. If successfully contacted, the mouth was briefly licked and nuzzled. The remaining playful attacks were gentle bites directed at the rump, and to a lesser extent, the top of the head. During serious fighting the top of the head and the rump are targets of attack, whereas the mouth is not. Licking and nuzzling the mouth was found to be a behavior performed by adult males at the beginning of sexual encounters. Therefore, play-fighting in juvenile hamsters cannot be thought of merely as a form of “mock fighting” since the principal target is seemingly sexual, not agonistic. The data also show that of the sexual body targets contacted, adult females are more likely to defend the mouth. In this way it is suggested that targets attacked and defended during juvenile play-fighting are derived from adult contexts in which such targets are defended. This hypothesis accounts for the prevalence of agonistic targets in the play-fighting of many species, and may provide a rationale for classifying those amicable targets that are competed for during play-fighting.     

Play-fighting differs from serious fighting in both target of attack and tactics of fighting in the laboratory rat Rattus norvegicus

Play-fighting is often difficult to differentiate from inhibited or immature serious fighting because both may utilize many of the same behavior patterns. In the rat the two behaviors involve different targets of attack. During play-fighting, snout or oral contact is directed at the opponent's nape of the neck, whereas during serious fighting, male residents mostly direct their bites at the intruder's rump. Although similar to those used in serious fighting, the behavior patterns used during play-fighting are modified to achieve the different targets of attack. Even though the tactics of attack and defense appear more adult-like with increasing age, the playful targets persist well into adulthood.     

A Cognitive Model of Dynamic Cooperation With Varied Interdependency Information

We analyze the dynamics of repeated interaction of two players in the Prisoner's Dilemma (PD) under various levels of interdependency information and propose an instance‐based learning cognitive model (IBL‐PD) to explain how cooperation emerges over time. Six hypotheses are tested regarding how a player accounts for an opponent's outcomes: the selfish hypothesis suggests ignoring information about the opponent and utilizing only the player's own outcomes; the extreme fairness hypothesis weighs the player's own and the opponent's outcomes equally; the moderate fairness hypothesis weighs the opponent's outcomes less than the player's own outcomes to various extents; the linear increasing hypothesis increasingly weighs the opponent's outcomes at a constant rate with repeated interactions; the hyperbolic discounting hypothesis increasingly and nonlinearly weighs the opponent's outcomes over time; and the dynamic expectations hypothesis dynamically adjusts the weight a player gives to the opponent's outcomes, according to the gap between the expected and the actual outcomes in each interaction. When players lack explicit feedback about their opponent's choices and outcomes, results are consistent with the selfish hypothesis; however, when this information is made explicit, the best predictions result from the dynamic expectations hypothesis.     

Do California ground squirrels (Spermophilus beecheyi) use ritualized syntactic cephalocaudal grooming as an agonistic signal?

Animal communication theory holds that many signals have evolved from nonsignal precursors. This field and laboratory study of California ground squirrels (Spermophilus beecheyi) provides evidence for the coexistence of such a precursor with its derived display. The precursor is an ancient, endogenously sequenced (syntactic) pattern of cephalocaudal grooming movements (CCGs) shared by all rodent suborders. The following evidence supports the hypothesis that a supernormal version of this pattern has been selected for signal function. Syntactic CCGs in the field (a) were more rigidly stereotyped than ordinary syntactic CCGs in the laboratory; (b) differed from laboratory syntactic CCGs in other ways that enhanced their conspicuousness, in part through exaggeration of the syntactic cephalocaudal pattern; (c) were associated with scent marking and social staring; and (d) were associated with intrasexual agonistic encounters that did not escalate to fighting.     

Conflict and metacognitive control: the mismatch-monitoring hypothesis of how others' knowledge states affect recall

Information about others' success in remembering is frequently available. For example, students taking an exam may assess its difficulty by monitoring when others turn in their exams. In two experiments, we investigated how rememberers use this information to guide recall. Participants studied paired associates, some semantically related (and thus easier to retrieve) and some unrelated (and thus harder). During a subsequent cued recall test, participants viewed fictive information about an opponent's accuracy on each item. In Experiment 1, participants responded to each cue once before seeing the opponent's performance and once afterwards. Participants reconsidered their responses least often when the opponent's accuracy matched the item difficulty (easy items the opponent recalled, hard items the opponent forgot) and most often when the opponent's accuracy and the item difficulty mismatched. When participants responded only after seeing the opponent's performance (Experiment 2), the same mismatch conditions that led to reconsideration even produced superior recall. These results suggest that rememberers monitor whether others' knowledge states accord or conflict with their own experience, and that this information shifts how they interrogate their memory and what they recall.     

Influencer les jugements de l'adversaire au cours des interactions sportives compétitives : un exemple en tennis de table

This study analysed the masking activity of table tennis players, and any activity attempting to influence opponent's perceptions. We studied the activity of five French table tennis players during national matches in reference to the course of action theory (Theureau, 1992). Matches were videotaped, and the players' verbalizations as they viewed the tapes were collected a posteriori. The data were analysed by 1) transcribing the players' actions and verbalizations, 2) decomposing their activity into elementary units of meaning, and 3) analysing the meaningful structures of the course of action. The results showed that a large part of the table tennis players activity attempts to influence opponent's judgments. This activity aims to 1) modify the opponent's emotional experience, and 2) influence the opponent's perception of adversarial relationship. It is expressed through strokes and behaviors not related to the game. Our results lead to a new perspective of table tennis matches analysis in term of collective activity and “shared context” (Salembier and Zouinar, 2004).     

Effect of body size on aggression in the ant,Cataglyphis niger (Hymenoptera; Formicidae)

In polymorphic ants, such as Cataglyphis niger, sterile individual workers from the same nest show some degree of variation in size and/or morphology. We studied whether worker size and size difference between opponents had an effect on aggression during conspecific encounters. Although the capacity to recognize nestmates was shared by all individuals, some patterns of agonistic behaviors were size related. Escape was mostly displayed by the small workers, and threat, associated with ritualized fights, by the large workers. As game theory predicted, ants of C. niger adjusted their level of aggression as a function of the size of the opponent. However, only large individuals used such assessment strategies, responding with escalation of aggression towards small workers and reduction of aggression towards large ones. On the contrary, small individuals behaved in the same manner whatever the opponent's size. Differences between both morphological castes were discussed with reference to the resource holding assessment models. Aggr. Behav. 25:369–379, 1999. © 1999 Wiley‐Liss, Inc.     

Instigation to aggression as a function of degree of defeat and the capacity for massive retaliation

Forty-eight subjects, half of whom were assigned to a condition of massive retaliation (MR) and half of whom were not (NMR), competed against a presumed opponent The loser on each trial received a shock of intensity level selected by the winner at the beginning of a trial and, simultaneously, feedback on the opponent's shock setting The winner received only feedback on the opponent's shock setting Defeat and feedback of aggressive intent (opponent's shock setting) were varied independently In the MR condition, an extreme level of shock could be selected Although its use was avoided, its psychological presence influenced perception of the opponent, aggressive behavior, and physiological arousal Consistent with previous findings, primary frustration was found to be a relatively inconsequential instigator to aggression compared to learned social attitudes     

Analysis of the targets and tactics of conspecific attack and predatory attack in northern grasshopper mice onychomys leucogaster

Comparisons of tactics of fighting between species are often difficult to make since the body targets attacked may differ. Thus it becomes difficult to assess whether differences in fighting tactics are due to species-specific differences in the tactics themselves or due to the different targets attacked. A solution to this problem is to analyse the tactics of a species that attacks different targets under different circumstances. In this way, differences in tactics can be more readily attributed to differences in targets. In this study, resident male northern grasshopper mice (Onychomys leucogaster) were tested against intruding male conspecifics and against laboratory mice (Mus musculus domesticus). Conspecifics were mainly bitten on the lower dorsum, whereas prey were bitten and killed by bites to the nape of the neck. Therefore, it was possible to analyze the tactics of attack by grasshopper mice when attacking different body targets. For example, in order to defend the lower dorsum and the nape, both intruding conspecifics and prey adopted an upright defensive posture. Resident grasshopper mice used the lateral attack tactic to gain access to the lower flanks but not the nape. This illustrates that the lateral attack tactic is not merely a tactic suitable for overcoming the upright defense tactic, but is used in this context only when the target attacked is on the opponent's posterior dorsum. Such withinpecies comparison enables the identification of the contextual rules which govern the use of fighting tactics. © 1992 Wiley-Liss, Inc.     

Performance and presence with head-movement produced motion parallax in simulated driving

Driving simulator studies can reveal relevant and valid aspects of driving behavior, but underestimation of distance and speed can negatively affect the driver’s performance, such as in performance of overtaking. One possible explanation for the underestimation of distance and speed is that two-dimensional projection of the visual scene disrupts the monocular-based illusory depth because of conflicting binocular and monocular information of depth. A possible solution might involve the strengthening of the monocular information so that the binocular information becomes less potent. In the present study, we used an advanced high-fidelity driving simulator to investigate whether adding the visual depth information of motion parallax from head movement affects sense of presence, judgment of distance and speed, and performance measures coupled with overtaking. The simulations included two types of driving scenario in which one was urban and the other was rural. The main results show no effect of this head-movement produced motion parallax on sense of presence, head movement, time to collision, distance judgment, or speed judgment. However, the results show an effect on lateral positioning. When initiating the overtaking maneuver there is a lateral positioning farther away from the road center as effect of the motion parallax in both types of scenario, which can be interpreted as indicating use of naturally occurring information that change behavior at overtaking. Nevertheless, only showing tendencies of effects, absent is any clear additional impact of this motion parallax in the simulated driving.     

The Role of Background Behavior in Televised Debates: Does Displaying Nonverbal Agreement and/or Disagreement Benefit Either Debater?

ABSTRACT

This study examined the effects of background nonverbal behavior displayed with the purpose of undermining one's opponent in televised debates. Students watched one of four versions of a televised debate. In each, while the speaking debater appeared on the main screen, subscreens displayed her nonspeaking opponent's background nonverbal behavior. In one version, the non-speaking debater remained “stone faced” during her opponent's speech, while in the other three she nonverbally displayed occasional disagreement, nearly constant disagreement, or both agreement and disagreement. After viewing the debates, students rated the debaters' credibility, appropriateness, objectivity, and debate skills, in addition to judging who won the debate. Analysis indicated that background nonverbal behavior influenced audience perceptions of debaters' credibility, appropriateness, objectivity, debate skill, and the extent to which the debate was won. These results suggest that adding nonverbal agreement to expressions of nonverbal disagreement do not reduce the negative impacts of communicating disagreement nonverbally during an opponent's speech and may in fact further decrease the audiences' perception of a debater's credibility and overall performance.     

Developing Anticipation Skills in Tennis Using On-Court Instruction: Perception versus Perception and Action

On-court instruction involving either Perception–action training or Perception-only training was used to improve anticipation skill in novice tennis players. A technical instruction group acted as a control. Participants' ability to anticipate an opponent's serve was assessed pre- and posttest using established on-court measures involving frame-by-frame video analysis. The perception–action and perception-only groups significantly improved their anticipatory performance from pretest to posttest. No pretest-to-posttest differences in anticipation skill were reported for the technical instruction group. The ability to anticipate an opponent's serve can be improved through on-court instruction where the relationship between key postural cues and subsequent performance is highlighted, and both practice and feedback are provided. No significant differences were observed between the perception–action and perception-only training groups, implying that either mode of training may be effective in enhancing perceptual skill in sport.     

Playful defensive responses in adult male rats depend on the status of the unfamiliar opponent

Adult male rats reared as pairmates from weaning were tested in a neutral arena with both members of another pair (one at a time). The unfamiliar pairs were found to engage in play fighting, although they were more likely to escalate the encounter into serious fighting than were pairs of familiar rats. Based on their within‐home pair behavior, each pairmate was designated as a dominant or a subordinate. When the test encounters between unfamiliar males were analyzed with regard to whether the pairings consisted of two dominants, two subordinates, or a mixed pair, the pattern of play fighting was found to be attenuated. Both dominants and subordinates were more likely to initiate playful encounters, to respond defensively during these encounters, and to do so using adult‐typical tactics of defense when paired with an unfamiliar rat that was dominant in its home cage. The mechanisms by which the home status of unfamiliar male rats can be identified by another male are discussed, particularly with regard to the role that play fighting may serve for this function. It is concluded that the data support the hypothesis that play fighting can be used by adult rats for social testing, which in this case seems to involve ascertaining the opponent's fighting capability. Aggr. Behav. 25:141–152, 1999. © 1999 Wiley‐Liss, Inc.     

On-court position and handedness in visual anticipation of stroke direction in tennis

ObjectivesIn racket sports, players integrate information picked up from their opponent's kinematics and contextual cues like on-court position into shot outcome anticipation. In view of suggested difficulties with anticipating left-handed opponents' action intentions, here we examined whether an opponent's handedness interacts with position-dependency in visual anticipation.Design and methodFollowing a 2 (Group) x 2 (Handedness) x 2 (Position) x 3 (Temporal Occlusion) factorial design, 20 tennis players and 20 non-players predicted directional outcome of temporally manipulated point-light animations of identical left- and right-handed forehand groundstrokes performed near vs. far from the court's midline.ResultsTennis players' response selection was mostly affected by an opponent's on-court position, particularly at an early stage of a hitting movement. Opponents' handedness affected response selection similarly in both groups (i.e., bias towards down-the-line predictions against left-handed strokes occluded at racket-ball-contact), but it did not interact with on-court position.ConclusionsFindings highlight that on-court position, and opponents' handedness to some extent as well, appears relevant for skilled visual anticipation in tennis.     

A sensory basis for the lateral difference in the newborn infant's response to somesthetic stimulation

To determine whether lateral differences in the newborn infant's response to somesthetic stimulation are a consequence of lateral differences in sensitivity or whether they are the result of lateral differences in motor tendencies, cardiac response to stimulation of the left and right perioral region was examined. Cardiac acceleration occurred significantly more frequently to stimulation of the right than to stimulation of the left. Ipsilateral head turning also occurred more reliably to stimulation of the infant's right side than to stimulation of his left side. Evidence of reliable lateral differences in cardiac acceleration responses even under conditions in which the effects of lateral differences in head turning were removed suggested that the laterally differentiated cardiac responsiveness was not merely a function of increased motor activity consequent upon stimulation of the infant's right side but reflected a difference in sensitivity at the infant's two sides as well.     

Working with psychosis: Part 2 – encounters with an omnipotent super-ego

This is the second in a series of four papers presenting work with a man suffering from a bipolar disorder. The present paper describes the second year of the work and my encounters with an omnipotent super-ego which made ferocious attacks on the work, especially when there were any developments. The attacks were particularly disabling because my own implacable super-ego was mobilized in the counter-transference. Consequently developments seemed to melt away as my patient and I were often reduced to mindless states. I came to understand that these omnipotent attacks were stirred by feelings of infantile helplessness and dependency, and were a means of trying to manage a dread of falling to pieces and unintegration.