The effects of age and intelligence on the dark-interval threshold

The threshold for the detection of the dark interval between two flashes of light (DIT) was investigated for 240 school children aged 6–17. It was found that the threshold showed a linear decline with chronological age. a finding attributed to physiological aging of the visual receptor system producing diminished persistence of the initial stimulus. This finding was counter to the expectation that the DIT would also indicate the growing potency of a higher-order cognitive process (temporal integration of stimulus traces) which would have caused the DIT to rise at some point along the chronological scale.     

Effects of age and asymmetrical stimulation on the subjective median plane

Changes in subjective median plane (SMP) as a result of asymmetrical visual and bodily stimulation were measured for a total of 260 Ss, age 5–17. Asymmetrical visual stimulation resulted in a readjustment of the SMP in the direction of stimulation, with a decline in magnitude of response as a function of age. Asymmetrical bodily stimulation was assimilated to by the younger children (SMP adjusted in the direction of stimulation), . and counteracted by the older children (age 8 and older). In the combination of the two, the effects of visual stimulation dominated those of bodily stimulation throughout the age range, possibly due to insufficient exposure to the asymmetrical bodily stimulation. Correlational analysis showed that CA, rather than MA, was the major variable associated with the results. The results are in general agreement with sensory-tonic theory, and are discussed in this light.     

The use of restricted environmental stimulation therapy (REST) in the treatment of essential hypertension: Two case studies

The previous paper (Suedfeld et al., 1982, pp. 553–559) reported the use of Restricted Environmental Stimulation Therapy (REST) in treating hypertension. This paper reports the response of two patients to 24 hr of a similar treatment offered as an adjunct to a weight-control program. In both patients blood pressure dropped immediately following the REST session and remained lower for up to 9 months. The initial drop in blood pressure was independent of weight loss. These results are interpreted in terms of a psychobiological model of self-regulation.     

Psychiatric referrals by a Juvenile court

A psychiatric service for children has attempted to make effective use of its limited resources by specialising in conjoint family therapy and in the establishment of consistent links with the network of other agencies and services working with parents and children. Since involvement with the law is seen as a point of crisis by a family and by the professionals already involved with it, the Juvenile Court is an important focal point in the network. The referral of a particular adolescent 'patient' to a child psychiatrist is described in detail, and the wider implications are discussed.     

The Type A Structured Interview: A behavioral assessment in the rough

The Type A behavior pattern is the focus of considerable research in behavioral medicine because of its causal relevance to coronary heart disease. The primary assessment of Type A behavior is a global rating made from a structured interview. From the perspective of behavioral assessment, this Structured Interview (SI) is important for two reasons. First, it provides an example of the superiority of an observed behavioral measure compared to self-report questionnaires for the assessment of an overt behavior pattern. Second, it provides a unique opportunity for the application of behavioral assessment technology. However, while the SI has demonstrated its clinical and research utility as a diagnostic procedure, its usefulness could be further enhanced in the areas of treatment selection and evaluation. The historical relationship between behavior and coronary heart disease is described. The development of the SI and the strengths of this assessment relative to other measurement approaches are reviewed. The standard questions and administration procedures for the interview are presented, along with several variations and modifications. Following this overview, the SI is discussed from the perspective of behavioral assessment.     

Index to Volume 28

Other Index

Index to Volume 28     

Not only base rates are neglected in the Engineer-Lawyer problem: An investigation of reasoners’ underutilization of complementarity

The standard Engineer-Lawyer problem (Kahneman & Tversky, 1973) points to the failure of reasoners to integrate mentioned base-rate information in arriving at likelihood estimates. Research in this area nevertheless has presupposed that participants respect complementarity (i.e., participants ensure that competing estimates add up to 100%). A survey of the literature leads us to doubt this pre-supposition. We propose that the participants' non-normative performance on the standard Engineer-Lawyer problem reflects a reluctance to view the task probabilistically and that normative responses become more prominent as probabilistic aspects of the task do. In the present experiments, we manipulated two kinds of probabilistic cues and determined the extent to which (1) base rates were integrated and (2) the complementarity constraint was respected. In Experiment 1, six versions of an Engineer-Lawyer-type problem (that varied three levels of cue to complementarity and two base rates) were presented. The results showed that base-rate integration increased as cues to complementary did. Experiment 2 confirmed that Gigerenzer, Hell, and Blank's (1988) random-draw paradigm facilitates base-rate integration; a second measure revealed that it also prompts respect for complementarity. In Experiment 3, we replicated two of our main findings in one procedure while controlling for the potential influence of extraneous task features. We discuss approaches that describe how probabilistic cues might prompt normative responding.     

Systematic mapping of developmental milestones in wild chimpanzees

Postnatal development is protracted relative to lifespan in many primates, including modern humans (Homo sapiens), facilitating the acquisition of key motor, communication and social skills that can maximize fitness later in life. Nevertheless, it remains unclear what evolutionary drivers led to extended immature periods. While the developmental milestone literature is well established in humans, insight we can gain from one‐species models is limited. By comparing the timing of relatable developmental milestones in a closely related species, the chimpanzee (Pan troglodytes), we can gain further understanding of the evolution of such an extended developmental phase. To date, few studies have specifically attempted to estimate developmental milestones in a manner comparable to the human literature, and existing studies lack sufficient sample sizes to estimate which milestones are more plastic with higher inter‐individual variation in the timing of their emergence. Here, we describe the emergence of gross motor, fine motor, social interaction and communication traits from a longitudinal sample of 19 wild chimpanzee infants (8 females and 11 males), Taï National Park, Côte d’Ivoire. Gross motor traits emerged at a mean of 4 months, communication traits at 12 months, social interaction traits at 14 months and fine motor traits at 15 months, with later emerging milestones demonstrating greater inter‐individual variation in the timing of the emergence. This pattern of milestone emergence is broadly comparable to observations in humans, suggesting selection for a prolonged infantile phase and that sustained skills development has a deep evolutionary history, with implications for theories on primate brain development.