Quantity judgments of sequentially presented food items by capuchin monkeys (Cebus apella)

Recent assessments have shown that capuchin monkeys, like chimpanzees and other Old World primate species, are sensitive to quantitative differences between sets of visible stimuli. In the present study, we examined capuchins’ performance in a more sophisticated quantity judgment task that required the ability to form representations of food quantities while viewing the quantities only one piece at a time. In three experiments, we presented monkeys with the choice between two sets of discrete homogeneous food items and allowed the monkeys to consume the set of their choice. In Experiments 1 and 2, monkeys compared an entirely visible food set to a second set, presented item-by-item into an opaque container. All monkeys exhibited high accuracy in choosing the larger set, even when the entirely visible set was presented last, preventing the use of one-to-one item correspondence to compare quantities. In Experiment 3, monkeys compared two sets that were each presented item-by-item into opaque containers, but at different rates to control for temporal cues. Some monkeys performed well in this experiment, though others exhibited near-chance performance, suggesting that this species’ ability to form representations of food quantities may be limited compared to previously tested species such as chimpanzees. Overall, these findings support the analog magnitude model of quantity representation as an explanation for capuchin monkeys’ quantification of sequentially presented food items.

Children's behavioral styles at age 3 are linked to their adult personality traits at age 26

We observed 1,000 3-year-old children who exhibited five temperament types: Undercontrolled, Inhibited, Confident, Reserved, and Well-adjusted. Twenty-three years later, we reexamined 96% of the children as adults, using multiple methods of comprehensive personality assessment, including both self- and informant-reports. These longitudinal data provide the longest and strongest evidence to date that children's early-emerging behavioral styles can foretell their characteristic behaviors, thoughts, and feelings as adults, pointing to the foundations of the human personality in the early years of life.     

Probability logic and combining evidence

In Hailperin 1996 Hailperin, T. 1996. Sentential Probability Logic, Bethlehem and London: Lehigh University Press and Associated University Presses.  [Google Scholar], in addition to its formal development of Probability Logic, there are many sections devoted to historical origins, illustrative examples, and discussion of related work by other authors. Here selected portions of its formal treatment are summarized and then used as a basis for a probability logic treatment of combining evidence.     

Studies in the Peripheral Retina: I. The Purkinje After-Image

Maslow, A. H., Ed. New Knowledge in Human Values. New York: Harper, 1959. Pp. 268. Reviewed by Henry Winthrop.     

On Unconscious Communications and Covert Enactments: Some Reflections on Their Role in the Analytic Situation

By means of an extended clinical example, this paper focuses on the impact that unconscious communications in the form of nonverbal behavior may have on the course and outcome of an analysis.

Responding to sudden catastrophic illnesses in their fathers, patient and analyst created enactments aimed at blinding them to hard truths about their relationships with this parent.

Serving as powerful resistances that led to a stalemate and all but ended treatment, these nonverbal enactments had to be recognized, confronted, and understood by both participants before analytic work could be resumed and progress achieved in this analysis.