Chronometric studies of numerical cognition in five-month-old infants

Developmental research suggests that some of the mechanisms that underlie numerical cognition are present and functional in human infancy. To investigate these mechanisms and their developmental course, psychologists have turned to behavioral and electrophysiological methods using briefly presented displays. These methods, however, depend on the assumption that young infants can extract numerical information rapidly. Here we test this assumption and begin to investigate the speed of numerical processing in five-month-old infants. Infants successfully discriminated between arrays of 4 vs. 8 dots on the basis of number when a new array appeared every 2 s, but not when a new array appeared every 1.0 or 1.5 s. These results suggest alternative interpretations of past findings, provide constraints on the design of future experiments, and introduce a new method for probing infants' enumeration process. Further experiments using this method provide initial evidence that infants' enumeration mechanism operates in parallel and yields increasingly accurate numerical representations over time, as does the enumeration mechanism used by adults in symbolic and non-symbolic tasks.     

Cognitive dissonance in groups: the consequences of disagreement

As L. Festinger (1957) argued, the social group is a source of cognitive dissonance as well as a vehicle for reducing it. That is, disagreement from others in a group generates dissonance, and subsequent movement toward group consensus reduces this negative tension. The authors conducted 3 studies to demonstrate group-induced dissonance. In the first, students in a group with others who ostensibly disagreed with them experienced greater dissonance discomfort than those in a group with others who agreed. Study 2 demonstrated that standard moderators of dissonance in past research--lack of choice and opportunity to self-affirm, similarly reduced dissonance discomfort generated by group disagreement. In Study 3, the dissonance induced by group disagreement was reduced through a variety of interpersonal strategies to achieve consensus, including persuading others, changing one's own position, and joining an attitudinally congenial group.     

Changing circumstances, disrupting habits

The present research investigated the mechanisms guiding habitual behavior, specifically, the stimulus cues that trigger habit performance. When usual contexts for performance change, habits cannot be cued by recurring stimuli, and performance should be disrupted. Thus, the exercising, newspaper reading, and TV watching habits of students transferring to a new university were found to survive the transfer only when aspects of the performance context did not change (e.g., participants continued to read the paper with others). In some cases, the disruption in habits also placed behavior under intentional control so that participants acted on their current intentions. Changes in circumstances also affected the favorability of intentions, but changes in intentions alone could not explain the disruption of habits. Furthermore, regardless of whether contexts changed, nonhabitual behavior was guided by intentions.     

A cross-cultural analysis of the behavior of women and men: implications for the origins of sex differences

This article evaluates theories of the origins of sex differences in human behavior. It reviews the cross-cultural evidence on the behavior of women and men in nonindustrial societies, especially the activities that contribute to the sex-typed division of labor and patriarchy. To explain the cross-cultural findings, the authors consider social constructionism, evolutionary psychology, and their own biosocial theory. Supporting the biosocial analysis, sex differences derive from the interaction between the physical specialization of the sexes, especially female reproductive capacity, and the economic and social structural aspects of societies. This biosocial approach treats the psychological attributes of women and men as emergent given the evolved characteristics of the sexes, their developmental experiences, and their situated activity in society.     

Assessing future possible selves by gender and socioeconomic status using the anticipated life history measure

This is a report from the first phase of a longitudinal study of the ways young adults imagine their future lives. The future possible selves of 223 18- and 19-year-old adults were examined using the Anticipated Life History measure (ALH), a psychological instrument prompting participants to describe their future life course from their 21st birthday until their death. When the ALH narratives were coded for presence/absence of life events, female participants were more likely to predict career choice, marriage, children, divorce, and death of spouse than their male counterparts; when coded for psychological qualities, female participants demonstrated greater psychological complexity and awareness of future life role choices and conflicts. Participants with lower SES wrote ALH narratives with fewer altruistic acts, less awareness of life role complexity, and fewer anticipated conflicts and their resolutions than those with higher SES.     

Childhood and adolescent onset conduct disorder: a test of the developmental taxonomy

Hypotheses generated by a developmental taxonomy that distinguishes between childhood and adolescent onset conduct disorders were tested. Hypotheses predicted that (1) individual and familial factors would be more strongly related to childhood onset conduct disorder, whereas ethnic minority status and exposure to deviant peers would be more strongly related to adolescent onset conduct disorder and (2) individuals with childhood onset disorder would be more likely to commit violent and victim oriented offenses than individuals with adolescent onset conduct disorder. The first hypothesis was strongly supported and the second hypothesis was partially supported. Implications for early identification of youth at risk for chronic offending are discussed.     

Perceptions of an old female eyewitness: is the older eyewitness believable?

Young adults rated an old female witness (82 years) to be less competent but more honest than a young female witness (28 years). The effect of age stereotyping on believability was assessed indirectly by using a variant of Loftus' misinformation paradigm. Regression analysis showed that the more competent a witness was perceived as being, the more influential was the misinformation she provided. This was true, however, only when the witness was young because the relatively lower competence of the old witness was associated with nonsignificant misinformation effects. These data suggest that negative beliefs associating incompetence with old age may compromise the believability of older eyewitnesses.     

Habituation of the proleg withdrawal reflex in Manduca sexta does not involve changes in motoneuron properties or depression at the sensorimotor synapse

Larvae of the hawkmoth, Manduca sexta, exhibit a defensive proleg withdrawal reflex in which deflection of mechanosensory hairs on the proleg tip (the planta) evokes retraction of the proleg. A previous behavioral study showed that this reflex habituates in response to repeated planta hair deflection and exhibits several other defining features of habituation. In a semi-intact preparation consisting of a proleg and its associated segmental ganglion, repeated deflection of a planta hair or electrical stimulation of its sensory neuron causes a neural correlate of habituation, manifested as a decrease in the number of action potentials evoked in the proleg motor nerve. Monosynaptic connections from planta hair sensory neurons to the principal planta retractor motoneuron exhibit several forms of activity-dependent plasticity. In the present study we recorded intracellularly from this motoneuron during repetitive electrical stimulation of a planta hair sensory neuron. The number of action potentials evoked in the motoneuron decreased significantly, representing a neural correlate of habituation. The motoneuron's resting membrane potential, input resistance. and spike threshold measured before and after repetitive stimulation did not differ between the stimulated group and a control group. Furthermore, the amplitude of the monosynaptic excitatory postsynaptic potential, as well as the magnitude of paired-pulse facilitation, evoked in the motoneuron by the sensory neuron did not change after repetitive stimulation. These results suggest that depression at the sensorimotor synapse does not contribute to reflex habituation. Rather, other mechanisms in the ganglion of the stimulated segment, such as changes in polysynaptic reflex pathways, appear to be responsible.     

Well-being during the coronavirus pandemic: The effect of big five personality and COVID-19 beliefs and behaviors

This study examined the relationship between personality traits, COVID-specific beliefs and behaviors, and well-being during the COVID-19 pandemic. In July 2020, at the onset of a second major lockdown, Australian adults (n = 1453) completed measures of Big Five personality, COVID beliefs and behaviors (i.e., belief in a rapid recovery, perceived risk, compliance, change in exercise, and change in interpersonal conflict), subjective well-being and COVID-specific well-being. Personality correlates of COVID-specific well-being differed from those with general life satisfaction. The benefits of conscientiousness were elevated whereas the benefits of extraversion and agreeableness were reduced. Neuroticism was related to greater perceived risk from the pandemic, elevated interpersonal conflict during the pandemic, and more pessimistic views about the rate at which society would recover from the pandemic. In contrast, conscientiousness was notably related to greater compliance with directions from public health authorities. While regression models showed that general well-being was largely explained by personality, COVID factors provided incremental prediction, and this was greatest when predicting COVID-specific well-being and lowest for global evaluations of life satisfaction. The observed prediction by beliefs and behaviors on well-being beyond personality, provides potential opportunities for targeted interventions to support the management of future novel stressors.