Errata

Corrections to:
K. Tanaka and S. Takimoto, "Effects of intrepersonal affect on fairness judgment" published in Japanese Psychological Review , 1997, Vol.39, No. 4
M. Ito et al., "Visual evoked potentails to geometric forms: Effects of spatial orientation" published in Japanese Psychological Review , 1997, Vol.39, No. 4
K. Ono, "Response stereotypy in humans maintained by response-contingent events" published in Japanese Psychological Review , 1997, Vol.39, No. 4     

Influence of dominance on the development of play fighting in pairs of male Syrian golden hamsters (Mesocricetus auratus)

In the highly social rat, male juvenile and adult subordinates initiate more playful contacts with dominant pairmates than vice versa. This study examined the effect of dominance on playful contacts in the relatively asocial golden hamster. Pairs of male hamsters were reared together from weaning, and their play was filmed in the juvenile (28-36 days) and the young adult (60-70 days) stages of development. By the adult stage, it became clear that one pairmate was dominant over the other. The dominant pairmate launched all aggressive attacks (i. e., bites to the lower flanks and rump), and the subordinate pairmate performed all the submissive gesturing (e. g., tail up submissive posture). Playful contact, which in this species involves gentle nibbling of the posterior cheeks, was more frequently launched by the dominant than by the subordinate. This was not only true at the adult stage, but also at the juvenile stage, before dominance-subordination relationships were sharply polarized. Therefore, it would appear that in the relatively asocial hamster, the subordinates tend to avoid playful contact with dominants. This is markedly different to rats, where the subordinates actively seek out and engage dominants in play. This contrast further supports our hypothesis that subordinate male rats use play as a means of maintaining familiarity with dominants. © 1993 Wiley-Liss, Inc.     

Initial excitatory conditioning with the truly random control procedure in rats: The effects of density of the conditioned stimulus

The present experiments were designed to test whether initial excitatory conditioning to a stimulus was obtained, using a within-subject design of the truly random control (TRC) procedure, and to examine the effects of the density of the conditioned stimulus on it. In Experiment 1, the effect of the three levels of CS density (50%, 25%, 20%) was assessed at six different stages of training, using the conditioned suppression of licking in rats. Although all of the groups given the TRC procedure showed evidence of initial excitatory conditioning, it was more marked in the group with the highest CS density than in the other groups. Experiment 2 confirmed the results of Experiment 1, using a between-subject design. The findings are in line with predictions from the Rescorla-Wagner model, and are discussed with reference to other contemporary theories of associative learning.     

Anxiolytic effects of repeated victory in male Wistar rats

Recurring evidence suggests that social stress has anxiogenic‐like effects in laboratory rodents. However, despite the fact that competitive situations are stressful, success in competitive situations reduces anxiety in humans. The aim of the present study was to investigate whether repeated experience of winning in aggressive encounters affects anxiety measures in laboratory rodents. Male rats were housed together with a female for 2 weeks. Cohabitation with females was necessary to induce high levels of aggressiveness in these animals. During the second week, half of the male rats were exposed daily for 30 min to an intruder of smaller size, and the other half remained undisturbed in their home cage. Group‐housed male rats were also used as controls. Residents attacked and defeated intruders, who did not retaliate. After the fifth encounter, all animals were tested for anxiety on the elevated plus‐maze. Repeated victory lowered anxiety measures considerably, despite the fact that aggressive encounters are stressful even for the victor. It is concluded that repeated victory has an anxiolytic action in male rats. The similarities with human data suggest that repeated winning in rats can be used as a laboratory model for success‐induced changes in human anxiety. Aggr. Behav. 26:257–261, 2000. © 2000 Wiley‐Liss, Inc.     

Male HIV-1 transgenic rats show reduced cocaine-maintained lever-pressing compared to F344 wildtype rats despite similar baseline locomotion

The HIV-1 transgenic (Tg) rat model is valuable for understanding HIV-associated neurocognitive disorders (HAND) and accompanying substance use and misuse. Tg and F344/NHsd wildtype (WT) rats were allowed to self-administer intrajugular cocaine. For the first 7 sessions, neither genotype self-administered cocaine (0.1 mg/kg/infusion) on a fixed ratio 1 schedule. We thus implemented a lever–cocaine “autoshaping” session followed by a series of manipulations changing dose and reinforcement schedule. Tg rats self-administered much less cocaine than WT rats throughout the study. Of 8 Tg rats, 5 modestly increased self-administration from sessions 36–50. Of those, only 3 showed a lever discrimination. Of 10 WT rats, 8 acquired robust self-administration by session 19; all WT rats self-administered cocaine by the end of the study. WT and Tg rats had similar baseline locomotor activity in the self-administration chamber suggesting that the low levels of cocaine intake in the Tg rats did not reflect a nonspecific motor impairment in this rat strain. Concomitant measurement of activity with self-administration revealed activity increases that followed increased cocaine intake. That relation held in Tg rats. Therefore, the present study provides evidence that HIV-1 Tg rats are less sensitive to the reinforcing effects of cocaine than their F344 WT counterparts.     

Ontogeny of agonistic behaviour in dispersing blind mole rats (spalax ehrenbergi)

The blind mole rat (Spalax ehrenbergi) is a solitary and aggressive fossorial rodent that inhabits its own individual tunnel system. Mole rats breed mainly in the winter, giving birth to a litter of three to four young on average [Nevo (1961) Mammalia 25:127–143]. Intraspecific interactions between adults occur mostly during the winter, which is the rainy season in Israel; after parturition, interactions occur between the mother and her offspring and between the siblings themselves until dispersal. Until now, the subterranean habitat of mole rats has prevented direct observation in the wild. Thus, there has been no direct evidence for the proximal factors that drive juvenile mole rats out of the maternal tunnel system as they shift from the social life-style of the young to the solitary life-style of the adult. In the present study, female mole rats were caught in the wild with their offspring and brought to the laboratory. The dispersal process of the young from the maternal nest was followed under two housing conditions: (1) restricted housing, simulating the physical conditions under which dispersal is delayed past the usual age, as often occurs during late winter floods in the field in areas of nonporous clay soils, and (2) nonrestricted housing, simulating the physical conditions that allow the young to disperse from their maternal tunnels at any time. In each housing condition, the mothers raised either one or three pups. During pup development, we monitored both maternal and juvenile agonistic variables during intraspecific interactions. Five major behavioural phases were identified during the ontogeny of the mole rat pups. Maternal aggression toward pups increased mainly in the first three phases of pup development, and sibling aggression increased from the third phase until dispersal. Under the restricted housing conditions, there was a delay in both the appearance of aggression in the “family group” as well as in dispersal age compared with the nonrestricted conditions. In the nonrestricted conditions, increased litter size resulted in delay in dispersal age. We suggest that the main proximate factor initiating natal dispersal is increased intolerance and aggression among siblings rather than maternal aggression. Only after the young began dispersing from the maternal tunnels did maternal aggression dramatically increase, thus preventing the offspring from returning. However, following floods, inhibition of aggression may enable the mole rat pups to stay with the family group and to disperse later when the physical conditions permit it. Aggr. Behav. 24:455–470, 1998. © 1998 Wiley-Liss, Inc.     

Effects of fluoxetine on play dominance in juvenile rats

In a series of three studies, we investigated the influence of a selective serotonin re-uptake inhibitor (fluoxetine) on the rough-and-tumble play of juvenile rats. In Experiment 1, both members of eight pairs of solitary-housed juvenile rats received either vehicle, 2.5, 5, or 10 mg/kg fluoxetine in a counterbalanced within-subject design 20 min before being allowed to play for 5 min periods on four successive test days. The 5 and 10 mg/kg pretreatments significantly reduced incidence of pins during play without affecting dorsal contacts. In Experiment 2, one member of each of 19 established play pairs received 5 mg/kg fluoxetine 20 min before play, while the other member received vehicle. Dominant rats showed no reduction in pins as a result of fluoxetine treatment, but subordinate rats who received fluoxetine exhibited significant reductions in pins. Subsequent dyadic analyses indicated that in pairs where the subordinate animal received fluoxetine, dominant animals maintained their pinning advantage over the 10 days of testing, but in pairs where the dominant animals received fluoxetine, this pinning asymmetry diminished. In Experiment 3, we replicated the above procedure with inexperienced play pairs, to control for the effects of prior social learning. Fluoxetine treatment (5 mg/kg) significantly reduced both pins and dorsal contacts in all treated rats. The results indicate that fluoxetine can reduce the playful pins of juvenile rats, but that prior social learning mediates the strength of these effects. © 1996 Wiley-Liss, Inc.     

Is There Such a Thing as “Christian” Sex?

It is challenging for Christian pastors and counselors to discuss human sexuality in ways which do not alienate liberals on the left, conservatives on the right, or biologists in the middle. Feminists frequently see males as dominating or insensitive, and conservative Christians sometimes feed into this by emphasizing patriarchal models of marriage as if this were the biblical paradigm for all time. Evolutionary biologists view sexuality primarily as a means of propagating the species. Into this cacophony of strident voices the Christian seeks to inject a calm but clear message: Christian sexuality is primarily a search for intimacy. In a culture obsessed with sexuality as entertainment, the followers of Christ call others to view human sexuality not primarily in terms of eroticism, power, or procreation, but rather in terms of psychological intimacy. From a biblical perspective, becoming one flesh, with one's mate also provides the occasion for becoming a co-creator with the eternal I AM. In addition to the procreational potential and orgasmic excitement provided by sexual intercourse, God intended for these encounters to be loaded with an abundance of psychological intimacy. Intimacy is the raison d'etre of sexual relationships. Intimacy provides sexuality with a quality that can mollify crises in the present life, and imbue sexuality with a splendor worthy of the next life as well.     

Effects of public posting,goal setting,and oral feedback on the skills of female soccer players

We evaluated the effects of public posting, goal setting, and oral feedback on the skills of 3 female high school soccer players during practice scrimmages. The dependent variables were the percentage of appropriate responses when the player (a) kept and maintained possession of the ball, (b) moved to an open position during a game restart (e.g., goal or corner kick), and (c) moved to an open position after passing the ball. We also assessed the extent to which changes in practice performances generalized to games. A social validity questionnaire was completed by both players and coaches to assess the acceptability of the intervention's goals, procedures, and outcomes. Results indicate that the intervention was effective in improving performances during practice scrimmages but produced limited generalization to game settings.