Aggressive behavior during the breeding season of adult female rhesus monkeys (Macaca mulatta)

The aggressive behavior of eight adult female rhesus living in a captive social group was studied prior to and during a breeding season extended by vasectomizing all the adult males in the group. Female reproductive status was ascertained by: recording all adult female-adult male copulations; detecting menstruation by vaginal swabbing; and analyzing serum progesterone levels by radioimmunoassay. Females showed more non-contact aggression during the breeding season, but wounding did not increase. Individual cycling females directed more frequent aggression to: particular adult males subordinate to them, subordinate females also in estrus, and (in a few cases) juveniles and infants.     

Social and nonsocial behaviors of adult rhesus monkeys after amygdalectomy in infancy or adulthood.

At 6 yr of age six female rhesus monkeys that had sustained bilateral amygdalectomy in infancy, and five intact controls, were transferred to an observation cage where behaviors were recorded while the monkeys were (a) alone, (b) paired with unfamiliar stimulus animals, and (c) paired with familiar monkeys from the opposite experimental group. The five adult controls then underwent amygdalectomy, and all tests were repeated with the infant- and adult-operated animals. Infant-operated monkeys changed behaviors more rapidly than did intact controls in social and nonsocial situations, and their activity levels were less modified after a 24-hr period in the observation cage. They were subordinate to intact controls but expressed less fear than did controls when briefly placed with an unfamiliar aggressive animal. Adult amygdalectomy produced many changes in behavior, but these aberrations were identical to those observed in like-age monkeys that had been amygdalectomized in infancy. Infant-operated monkeys demonstrated more behavioral deficits at 6 yr than they had earlier in life.     

Individuality in coo calls of adult male golden snub-nosed monkeys (Rhinopithecus roxellana) living in a multilevel society

Animal Cognition - Vocal individuality is a prerequisite for individual recognition, especially when visual and chemical cues are not available or effective. Vocalizations encoding information of...     

Intraday feeding patterns in infant rhesus monkeys and the effects of missing a meal

During the first month of life, infant rhesus monkeys (N = 96) were fed 7 times a day for the first 21 days and were fed 6 times a day thereafter. Fifty monkeys were fed SMA, a formula designed for human infants (9% protein, 43% carbohydrate, and 48% fat); 46 were fed one of three laboratory-confected diets varying in the amount of protein and carbohydrates provided. Although the diets had differential effects on weight gain, overall daily consumption was practically unaffected. A characteristic pattern was evident soon after birth: The first meal of the day (8:00 AM) was one of the largest, and the following two meals were usually the smallest; the next peak spanned the 4:00 PM and 8:00 PM feedings. The meal following a missed meal was slightly larger than normal. To some extent, the large meal at 8:00 AM can be attributed to the 10-hr absence of food during the night, but the peak at 4:00 PM and 8:00 PM cannot be so accounted for. The adult bicuspid pattern of eating hence appears to develop very early in life.     

Selective associations in the observational conditioning of fear in rhesus monkeys

Three experiments explored the issue of selective associations in the observational conditioning of fear. Experiment 1 results indicated that observer rhesus monkeys acquired a fear of snakes through watching videotapes of model monkeys behaving fearfully with snakes. In Experiment 2, observers watched edited videotapes that showed models reacting either fearfully to toy snakes and nonfearfully to artificial flowers (SN+/FL-) or vice versa (FL+/SN-). SN+/FL- observers acquired a fear of snakes but not of flowers; FL+/SN- observers did not acquire a fear of either stimulus. In Experiment 3, monkeys solved complex appetitive discriminative (PAN) problems at comparable rates regardless of whether the discriminative stimuli were the videotaped snake or the flower stimuli used in Experiment 2. Thus, monkeys appear to selectively associate snakes with fear.     

Protein deprivation in primates: VI. Food preferences of adult rhesus monkeys maintained on low-protein diets.

Three groups of adult female rhesus monkeys, maintained on low-protein diets (.5 gm, 1 gm, and 2 gm protein per kg body weight, were compared with a control group (4 gm protein per kg body weight) on a food-preference task. Food responsiveness was assessed by presenting 8 small pieces of a certain food, equally spaced about the perimeter of a turntable attached to the home cage, and recording number of pieces taken, number of pieces eaten, and elapsed time for taking all 8 pieces. 21 different foods were used in sequence, 3 each from the following 7 categories: cheese, meat, vegetable, nut, cereal, fruit, and candy. Scores on all 3 measures were highly correlated, and the order of preference was generally the same for all groups. The 2 lowest-protein groups accepted more foods at the lower end of the palatability spectrum than did either the 4-gm or the 2-gm group. There was a tendency for the foods least preferred by the protein-deprived monkeys to be themselves high in protein. Thus, although protein deprivation appears to increase the catholicity of food preference, there is no corresponding increase in the relationship between palatability and protein content.     

Infants of chronically depressed mothers learn in response to male, but not female, infant-directed speech

Previous research using a conditioned-attention paradigm demonstrated that 4-month-old infants of depressed mothers (a) failed to acquire associations when a segment of their mothers' infant-directed (ID) speech signaled the presentation of a smiling face but (b) did acquire associations when a segment of an unfamiliar nondepressed mother's ID speech signaled the face (P. S. Kaplan, J. -A. Bachorowski, M. J. Smoski, & W. J. Hudenko, 2002). In the present study, 5- to 13-month-old infants of depressed mothers failed to acquire associations when either their own mothers' (Experiment 1) or an unfamiliar nondepressed mother's (Experiments 1 and 2) ID speech signaled a face. However, these infants acquired associations when a segment of an unfamiliar nondepressed father's ID speech served as the signal (Experiment 2). One possible explanation of these results is that infants of depressed mothers selectively "tune out" ID speech from their mothers and from other, nondepressed, women.     

Cardiac pacing and the law of initial value in rhesus monkeys

A cardiac pacemaker was used to produce a wide range of pre-CS heart rates in Pavlovian conditioning, and correlations were computed between pre-CS and CS heart rates. Two rhesus monkeys were presented trials in which 30 sec of light (CS) was followed by a brief electric shock (UCS). Pacing rates during the inter-trial intervals were varied from 150 to 350 bpm. Pacing was discontinued during CS. Unpaced control sessions showed that the maximum heart rate in CS on each trial was proportional to the pre-CS heart rate. Following pacing, however, heart rate in CS did not depend on the pacing rate; rather, the rates were not different from those of the unpaced control sessions. Pacing at high rates shifted the maximum heart rate toward the end of CS.     

Aggressive behavior in the free-ranging rhesus monkeys of kathmandu,nepal

We present a composite sample of the aggressive behavior of free-ranging rhesus monkeys (Macaca mulatta), recorded at two temples in Kathmandu, Nepal. We analyze the total number and the rate per monkey of threats, chases, attacks, fights, and aggressive acts directed at other species (principally humans), in order to elucidate social dynamics of the troop as a whole. Our 1,506 hours of observation were divided among the four seasons; between a.m. and p.m.; and among a temple yard, two parklands, and a forested garden. We found seasonal patterns to be the most important correlates of aggressive behavior. Habitat was a modulating influence, and time of day was the least important factor. Rates of aggression were generally higher per male monkey than per female. In terms of total aggression recorded, however, females instigated significantly more than males, both in encounters between monkeys and in aggression against other species. This finding is consistent with the females' greater numbers in the troop and with their lifelong membership in the troop. Analysis of behavior by social groups, rather than by individual rates, points up the iomportance of adult females and their social stability in troop behavior.     

Impaired performance from brief social isolation of rhesus monkeys (Macaca mulatta): a multiple video-task assessment

Social isolation has been demonstrated to produce profound and lasting psychological effects in young primates. In the present investigation, two adult rhesus monkeys (Macaca mulatta) were isolated from one another for up to 6 days and tested on 7 video tasks designed to assess psychomotor and cognitive functioning. Both the number and the quality (i.e., speed and accuracy) of responses were significantly compromised in the social isolation condition relative to levels in which the animals were tested together. It is argued that adult rhesus are susceptible to performance disruption by even relatively brief social isolation, and that these effects can best be assessed by a battery of complex and sensitive measures.     

Relative reinforcer magnitude under a nonindependent concurrent schedule of cocaine reinforcement in rhesus monkeys.

Lever pressing by three rhesus monkeys was maintained under a two-lever concurrent schedule of cocaine reinforcement. Responding on one lever (constant-dose lever) produced a constant dose of 0.05 or 0.1 mg/kg/injection arranged according to a variable-interval 1-min schedule. Responding on the other lever (variable-dose lever) produced a comparison dose of cocaine (0.013 to 0.8 mg/kg/injection), also under a variable-interval 1-min schedule. The two variable-interval schedules were made nonindependent by arranging that the assignment of a reinforcer by one schedule inactivated the second schedule until the assigned reinforcer had been obtained. This modification ensured that the two cocaine doses were obtained with approximately equal frequency, regardless of the distribution of the subject's responding. Preference, indicated by relative response frequency on the variable-dose lever, was almost always for the larger of the doses and was a monotonic function of the comparison dose, except at the highest doses. Preferences at the highest comparison doses may have resulted from the low overall response rates exhibited at these doses. Relative response frequencies on the variable-dose lever roughly matched relative reinforcer magnitude (mg/kg/injection available on the variable-dose lever divided by the sum of mg/kg/injections available on each lever).     

Developmental consequences of behavioral inhibition: a model in rhesus monkeys (Macaca mulatta)

In children, behavioral inhibition is characterized by a disposition to withdraw in the presence of strangers and novel situations. Later in life, behavioral inhibition can result in an increased risk for anxiety and depression and a decrease in social behavior. We selected rhesus monkeys that, during infancy, showed evidence of behavioral inhibition in response to separation, and contrasted them with non‐inhibited peers. To understand the development of behavioral inhibition at juvenile age, we collected behavioral data in response to relocation; in response to a human intruder challenge; and in naturalistic outdoor field corrals. At 4 years of age (young adulthood), we again collected behavioral data in the outdoor field corrals to understand the adult social consequences of behavioral inhibition. We also included sex, dominance rank, and number of available kin in our analyses. Finally, to understand the consistency in behavior in behaviorally inhibited animals, we conducted exploratory analyses contrasting behaviorally inhibited animals that showed high vs. low durations of non‐social behaviors as adults. At juvenile age, behaviorally inhibited animals continued to show behavioral differences in the novel testing room and during the human intruder challenge, generally showing evidence of greater anxiety and emotionality compared to non‐inhibited controls. In their outdoor corrals, behaviorally inhibited juveniles spent more time alone and less time in proximity and grooming with mother and other adult females. In young adulthood, we found that behavioral inhibition was not related to time spent alone. We did find that duration of time alone in adulthood was related to time alone exhibited as juveniles; sex, dominance rank, or the number of kin were not influential in adult non‐social duration, either as main effects or as moderators. Finally, exploratory analyses revealed that behaviorally inhibited females that were more sociable (less time spent alone) as adults had spent more time grooming as juveniles, suggesting that high‐quality social interaction at a young age might mitigate the social consequences of behavioral inhibition. Overall, we believe that the many similarities with the human data that we found suggest that this monkey model of naturally occurring behavioral inhibition can be valuable for understanding social development.     

Effects of the menstrual cycle on looking preferences for faces in female rhesus monkeys

Fluctuations of ovarian hormones across the menstrual cycle influence a variety of social and cognitive behaviors in primates. For example, female rhesus monkeys exhibit heightened interest for males and increased agonistic interactions with other females during periods of high estrogen levels. In the present study, we hypothesized that females’ preference for males during periods of high estrogen levels is also expressed at the level of face perception. We tested four intact females on two face-tasks involving neutral portraits of male and female rhesus monkeys, chimpanzees and humans. In the visual preference task (VP), monkeys had to touch a button to view a face image. The image remained on the screen as long as the button was touched, and the duration of pressing was taken as an index of the monkey's looking time for the face stimulus. In the Face-Delayed Recognition Span Test (Face-DRST), monkeys were rewarded for touching the new face in an increasing number of serially presented faces. Monkeys were tested 5 days a week across one menstrual cycle. Blood was collected every other day for analysis of estradiol and progesterone. Two of the four females were cycling at the time of testing. We did not find an influence of the cycle on Face-DRST, likely due to a floor effect. In the VP however, the two cycling individuals looked longer at conspecific male faces than female faces during the peri-ovulatory period of the cycle. Such effects were absent for human and chimpanzee faces and for the two noncycling subjects. These data suggest that ovarian hormones may influence females’ preferences for specific faces, with heightened preference for male faces during the peri-ovulatory period of the cycle. Heightened interest for stimuli of significant reproductive relevance during periods of high conception risk may help guide social and sexual behavior in the rhesus monkey.     

Church and choices: a qualitative exploration of lived sexual values in young adult women

This qualitative research article discusses three crucial encounters in the sexuality education experiences of young adult women who were raised Catholic by drawing from the analyzed interview data of 15 such women. Using the framework of lived theologies, the author argues that understanding the impact of these encounters helps theological scholars better understand the way that young adults from religious backgrounds make decisions about relationships and sexuality. The young adult women interviewed for this research highlight a defensive posture in sexual decision-making that reflects poor preparation for the realities of relationships and a lack of opportunities to clarify and specify their own sexual values prior to these occasions.