Journal of Comparative Psychology最新文献

We studied mother-infant relationships and infant independence in wild Geoffroy's spider monkeys (Ateles geoffroyi) during the first 3 years of infant life. We used 15-min focal sampling to collect data on mother-infant interactions and infant behavior in 12 mother-infant dyads in the Yucatan peninsula, Mexico. Data were analyzed using generalized linear mixed models. Newborns spent almost all their time in proximity and in contact with their mothers. The time infants spent within one-arm reach from the mother decreased with age, and the infant was primarily responsible for maintaining proximity. The time infants spent farther than 8 m from the mother, in independent locomotion, exploration, and proximity with group members other than the mother increased with age. We identified two developmental periods associated with critical milestones of infant independence: the first at 8 to 10 months when independent locomotion and exploration began, and the proportion of time in proximity with group members other than the mother increased and the second at 19 to 21 months when the mother's rejection started, maternal carrying ended and mother's help, in the form of bridging canopy gaps, peaked. Compared with other primate species of similar size, Ateles geoffroyi have an extended dependence period, which could be related to the cognitive and developmental challenges imposed by their socioecological characteristics. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Unlike nonhuman primates, individual differences between humans in dominance do not appear as broad personality factors. This may be attributable to differences between the questionnaires used to study human and nonhuman primate personality. Alternatively, this may reflect differences in the organization of personality in humans and nonhuman primates. To determine which of these possibilities was most likely, 1,147 participants were recruited and asked to rate their personality and/or that of somebody else on the Hominoid Personality Questionnaire (HPQ), which has been used to study nonhuman primate personality. A large subset of these participants (~80%) also completed self- and/or rater reports of one of three questionnaires used to measure human personality. Exploratory factor analyses of HPQ rater report data yielded five factors. These factors correlated mostly in expected ways with scales from questionnaires used to study human personality. Exploratory factor analyses of HPQ self-report data yielded no clear number of factors and no consistent evidence with respect to the presence of a dominance factor. Subsequent analyses compared HPQ scales that represented dominance factors in chimpanzees, bonobos, mountain gorillas, and orangutans to scales derived from the Revised NEO Personality Inventory, including Fearless Dominance, which combined Neuroticism, Agreeableness, Conscientiousness, and Extraversion facets, Emotional Stability (the inverse of Neuroticism), and Extraversion's Assertiveness facet. Fearless Dominance and Assertiveness were most like the great ape dominance factors. The absence of human dominance factors, therefore, appears to reflect present or past social conditions of our species. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

On the surface, the fields of animal communication and human linguistics have arrived at conflicting theories and conclusions with respect to the effect of social complexity on communicative complexity. For example, an increase in group size is argued to have opposite consequences on human versus animal communication systems: although an increase in human community size leads to some types of language simplification, an increase in animal group size leads to an increase in signal complexity. But do human and animal communication systems really show such a fundamental discrepancy? Our key message is that the tension between these two adjacent fields is the result of (a) a focus on different levels of analysis (namely, signal variation or grammar-like rules) and (b) an inconsistent use of terminology (namely, the terms "simple" and "complex"). By disentangling and clarifying these terms with respect to different measures of communicative complexity, we show that although animal and human communication systems indeed show some contradictory effects with respect to signal variability, they actually display essentially the same patterns with respect to grammar-like structure. This is despite the fact that the definitions of complexity and simplicity are actually aligned for signal variability, but diverge for grammatical structure. We conclude by advocating for the use of more objective and descriptive terms instead of terms such as "complexity," which can be applied uniformly for human and animal communication systems-leading to comparable descriptions of findings across species and promoting a more productive dialogue between fields. (PsycInfo Database Record (c) 2022 APA, all rights reserved).