Cardiac-somatic integration: An index of visual attention

Eighteen 15-week-old, normal full-term infants were presented with photographic slides of a human facial expression. The infant's heart rate, body movement, and visual attention were recorded simultaneously. The results showed that heart rate and body movement were significantly correlated during visual attention but not during inattention. Both heart rate and body movement decelerated significantly when the infants visually attended to the target stimulus. The results are discussed with reference to cardiac-somatic integration in early infancy and its implication as a possible index of attention.     

Suppressing valid inferences with conditionals

Three experiments are reported which show that in certain contexts subjects reject instances of the valid modus ponens and modus tollens inference form in conditional arguments. For example, when a conditional premise, such as: If she meets her friend then she will go to a play, is accompanied by a conditional containing an additional requirement: If she has enough money then she will go to a play, subjects reject the inference from the categorical premise: She meets her friend, to the conclusion: She will go to a play. Other contexts suppress the conditional fallacies. The first experiment demonstrates the effects of context on conditional reasoning. The second experiment shows that the inference suppression disappears when the categorical premise refers to both of the antecedents, such as: She meets her friend and she has enough money. In this case, subjects make both the valid inferences and the fallacies, regardless of the contextual information. The third experiment establishes that when subjects are given general information about the duration of a situation in which a conditional inducement was uttered, such as: If you shout then I will shoot you, they reject both the valid inferences and the fallacies. The results suggest that the interpretation of premises plays an even more central role in reasoning than has previously been admitted.     

Chronic self-destructiveness: Conceptualization,measurement, and initial validation of the construct

Individual differences in various behaviors suggest that those who are primarily motivated by current emotional factors are more likely than those motivated by more distant cognitive considerations to engage in acts that are ultimately self-destructive. To assess and explore these behavioral differences, 12 samples of undergraduate subjects, totaling 864 (527 females, 337 males), a group of 15 businesswomen, and 111 male VA patients were used to develop a measure of this construct in a series of reliability and construct validity studies. By means of internal-consistency item analyses, two cross-validated 52-item measures of chronic self-destructiveness were constructed for males and females. Reliability was established with respect to internal consistency (alpha coefficients range from .73 to .97) and temporal consistency over a 1-month period (test-retest correlations range from .90 to .98). There is a slight drop in chronic self-destructiveness scores across age groups. Test scores were found to be positively related to external locus of control, negatively related to Type A coronary-prone behavior, and unrelated to either social desirability response set or need for achievement. Individuals high in chronic self-destructiveness, compared to those with low scores, are more likely to be in treatment for drug or alcohol abuse, to report having cheated in courses, to have had traffic violations, to report having gone through a rebellious stage in adolescence, and to postpone obtaining a medical test for cancer. Chronic self-destructiveness appears to be a personality dimension that affects behavior across a wide range of ages and situations.We wish to thank John Wapner for his assistance in obtaining data in the clinical sample.     

Literacy acquisition influences children's rapid automatized naming

Previous research has established that learning to read improves children's performance on reading‐related phonological tasks, including phoneme awareness (PA) and nonword repetition. Few studies have investigated whether literacy acquisition also promotes children's rapid automatized naming (RAN). We tested the hypothesis that literacy acquisition should influence RAN in an international, longitudinal population sample of twins. Cross‐lagged path models evaluated the relationships among literacy, PA, and RAN across four time points from pre‐kindergarten through grade 4. Consistent with previous research, literacy showed bidirectional relationships with reading‐related oral language skills. We found novel evidence for an effect of earlier literacy on later RAN, which was most evident in children at early phases of literacy development. In contrast, the influence of earlier RAN on later literacy was predominant among older children. These findings imply that the association between these two related skills is moderated by development. Implications for models of reading development and for dyslexia research are discussed.     

Local traditions in gorilla manual skill: evidence for observational learning of behavioral organization

Elaborate manual skills of food processing are known in several species of great ape; but their manner of acquisition is controversial. Local, “cultural” traditions show the influence of social learning, but it is uncertain whether this includes the ability to imitate the organization of behavior. Dispute has centered on whether program-level imitation contributes to the acquisition of feeding techniques in gorillas. Here, we show that captive western gorillas at Port Lympne, Kent, have developed a group-wide habit of feeding on nettles, using two techniques. We compare their nettle processing behavior with that of wild mountain gorillas in Rwanda. Both populations are similar in their repertoires of action elements, and in developing multi-step techniques for food processing, with coordinated asymmetric actions of the hands and iteration of parts of a process as “subroutines”. Crucially, however, the two populations deal in different ways with the special challenges presented by nettle stings, with consistently different organizations of action elements. We conclude that, while an elaborate repertoire of manual actions and the ability to develop complex manual skills are natural characteristics of gorillas, the inter-site differences in nettle-eating technique are best explained as a consequence of social transmission. According to this explanation, gorillas can copy aspects of program organization from the behavior of others and they use this ability when learning how to eat nettles, resulting in consistent styles of processing by most individuals at each different site; like other great apes, gorillas have the precursor abilities for developing culture.