Cardiac correlates of individual recognition in the chimpanzee (Pan troglodytes)

The ability of a chimpanzee to recognize individuals depicted in photographs was evaluated through the use of heart rate measures. Heart rate was recorded before and during photographic projections of human caregivers, familiar individuals, strangers, and blank control slides. In the absence of explicit training or reinforcement, the chimpanzee displayed a differential pattern of heart rate response to the stimulus categories. Although heart rate responses to all stimuli were predominantly deceleratory, the photographs of caregivers yielded consistently larger responses than other stimuli. Results indicate that the chimpanzee is able to recognize individual humans from novel photographic representations and that heart rate can provide an objective measure of such recognition.     

Numerical competence in a chimpanzee (Pan troglodytes)

A chimpanzee (Pan troglodytes), trained to count foods and objects by using Arabic numbers, demonstrated the ability to sum arrays of 0-4 food items placed in 2 of 3 possible sites. To address representational use of numbers, we next baited sites with Arabic numbers as stimuli. In both cases performance was significantly above chance from the first sessions, which suggests that without explicit training in combining arrays, the animal was able to select the correct arithmetic sum for arrays of foods or Arabic numbers under novel test conditions. These findings demonstrate that counting strategies and the representational use of numbers lie within the cognitive domain of the chimpanzee and compare favorably with the spontaneous use of addition algorithms demonstrated in preschool children.     

Semi-wild chimpanzees open hard-shelled fruits differently across communities

Researchers investigating the evolutionary roots of human culture have turned to comparing behaviours across nonhuman primate communities, with tool-based foraging in particular receiving much attention. This study examined whether natural extractive foraging behaviours other than tool selection differed across nonhuman primate colonies that had the same foods available. Specifically, the behaviours applied to open the hard-shelled fruits of Strychnos spp. were examined in three socially separate, semi-wild colonies of chimpanzees (Pan troglodytes) that lived under shared ecological conditions at Chimfunshi Wildlife Orphanage, and were comparable in their genetic makeup. The chimpanzees (N = 56) consistently applied six techniques to open these fruits. GLMM results revealed differences in the number of combined technique types to open fruits across the colonies. They also showed colony differences in the application of three specific techniques. Two techniques (full biting and fruit cracking) were entirely absent in some colonies. This study provides empirical evidence that natural hard-shelled fruit-opening behaviours are distinct across chimpanzee colonies, differences that most likely have not resulted from ecological and genetic reasons.     

Apes communicate about absent and displaced objects: methodology matters

Displaced reference is the ability to refer to an item that has been moved (displaced) in space and/or time, and has been called one of the true hallmarks of referential communication. Several studies suggest that nonhuman primates have this capability, but a recent experiment concluded that in a specific situation (absent entities), human infants display displaced reference but chimpanzees do not. Here, we show that chimpanzees and bonobos of diverse rearing histories are capable of displaced reference to absent and displaced objects. It is likely that some of the conflicting findings from animal cognition studies are due to relatively minor methodological differences, but are compounded by interpretation errors. Comparative studies are of great importance in elucidating the evolution of human cognition; however, greater care must be taken with methodology and interpretation for these studies to accurately reflect species differences.     

¿Se da lenguaje en los simios?

RESUMEN

Los autores revisan la evidencia en favor de la capacidad de representación simbólica en simios, afirmando que todos los programas de lenguaje parten de la misma suposición: considerar signos, lexigramas y fichas de plástico como verdaderos elementos de vocabulario siempre que los simios sean capaces de ejecutar la etiqueta conductual correcta en presencia del correspondiente hecho u objeto. Consideran crucial el problema de la equivalencia entre capacidad de etiquetar y de representar simbólicamente y manifiestan que no se ha desarrollado ningún marco teórico dentro de la psicología animal que permita distinguir respuestas discriminativas condicionadas de respuestas simbólico-representacionales. Afirman que según sus investigaciones recientes la habilidad para utilizar símbolos de forma representativa puede ser alcanzada por chimpancés, pero no es posible deducir de la simple asociación entre etiqueta y objeto la existencia de esta función de representación o simbolización. También abordan la comunicación protolingüística de niños comparándola con la de chimpancés y desarrollan el concepto de verdadera simbolización, concluyendo que los estudios sobre el lenguaje de los simios han fracasado a la hora de obtener la verdadera simbolización en parte debido a que se han centrado casi exclusivamente en el aspecto de la producción, descuidando la competencia receptiva.     

Mental Health Stereotypes About Gay Men

Three studies were conducted to examine the mental health stereotypes about gay men among college student and therapist trainee samples. Results from Study 1 indicated that (a) college students and therapist trainees endorsed a stereotype of the mental health of gay men that was similar in terms of its content and strength, and (b) the stereotype was consistent with five DSM-IV-TR disorder categories: mood, anxiety, sexual and gender identity, eating, and personality disorders. In Study 2 and 3 we investigated whether homophobia or a tendency to report cultural beliefs could account for the lack of difference between college students and therapist trainees. Results did not support either explanation.     

A public versus private administration of the implicit association test

This research includes two experiments that examined (a) whether the assessment situation in which individuals complete an implicit measure of bias alters their responses and (b) whether the hypothesized effect of the assessment situation on implicitly assessed bias reflects socially desirable responding. Participants in Experiment 1 (N = 151) completed an IAT measuring bias toward homosexuality in either a public or a private assessment situation. Consistent with studies of explicitly assessed attitudes, implicitly assessed bias toward homosexuality was significantly lower when assessed in a public versus a private assessment situation. Participants in Experiment 2 (N = 102) completed an IAT measuring bias toward homosexuality in a public assessment situation under a bogus pipeline or no‐bogus pipeline condition. Results indicated that participants' implicitly assessed bias did not significantly differ across these conditions. The authors discuss these findings in terms of possible automatic processes affecting the malleability of implicitly assessed attitudes. Copyright © 2006 John Wiley & Sons, Ltd.     

A Review of Experimental Studies of Explicit and Implicit Bias Among Counselors

Bias is a central concept in multicultural competency, but counseling research has largely ignored implicit bias. A review of bias research in counseling indicates that increased focus on implicit bias is warranted because counselors tend not to report explicit bias and have implicit bias that diverges from their self‐reported attitudes. El sesgo es un concepto esencial para la competencia multicultural, pero la investigación relacionada con la consejería ha ignorado en su mayoría el sesgo implícito. Una revisión de los estudios sobre consejería indica que está justificado aumentar la atención hacia el sesgo implícito, porque los consejeros tienden a no informar sobre el sesgo explícito y tienen sesgos implícitos que no se corresponden con sus actitudes autoinformadas     

Gendered Mental Disorders: Masculine and Feminine Stereotypes About Mental Disorders and Their Relation to Stigma

Research indicates that stereotypes can intersect. For example, the intersection of stereotypes about gender and mental disorders could result in perceptions of gendered mental disorders. In the current research, Studies 1 and 2 showed that people view specific disorders as being masculine or feminine. The masculine stereotype included antisocial personality disorder, addictions, and paraphilias. The feminine stereotype included eating disorders, histrionic personality disorder, body dysmorphia, and orgasmic disorder. In both studies, the perception of disorders as masculine was positively correlated with stigma. Study 3 showed that the positive correlation between masculinity and stigma also occurred when examining specific symptoms rather than full mental disorders. The findings provide further evidence for the intersection of stereotypes and indicate a novel factor in the understanding of stigma.     

Simian scribbles: a reappraisal of drawing in the chimpanzee (Pan troglodytes)

Three chimpanzees (Pan troglodytes) were provided with 18 different stimulus pages for drawing. The resulting 618 drawings were coded for drawn marks, and results were compared with early reports on ape drawing (Morris, 1962; Schiller, 1951) and with more recent systematic studies (Smith, 1973). The findings of the present study confirm Smith's observations of a tendency for the animals to draw closer to the center and toward the bottom of the page. No evidence for perceptual balancing was observed in drawings produced on pages with lateral figures, nor was any evidence for closure apparent with complex figures. The present results agree with earlier findings that chimpanzees will engage in drawing activities without training or reinforcement, and this behavior may reflect their intrinsic interest in exploratory and manipulative play.