Altruism between romantic partners: Biological offspring as a genetic bridge between altruist and recipient

When the cost of altruism is low, individuals are more likely to help non-kin (i.e., friends and romantic partners) than kin. This trend is thought to reflect the fact that people tend to be emotionally closer with friends and romantic partners than kin. However, as the cost of altruism increases, altruistic preference shifts to kin. The present study highlights this phenomenon by examining altruism between siblings, romantic partners, romantic partners who have biological children together, and romantic partners who have adopted children together. Participants (n = 203) completed a questionnaire about altruism in low-, medium-, and high-cost situations. Participants gave more low-cost help to their romantic partners (regardless of whether they had a child together) than their siblings. More medium-cost help was given to romantic partners who had a child (biological and adopted) than siblings and romantic partners without children. In the high-cost condition, the estimated altruistic tendencies were stronger toward siblings and romantic partners who have a biological child than toward romantic partners with no children and partners with adopted children. Participants also believed they were more altruistic than their siblings and romantic partners.     

Atheism, Morality and Meaning

Book reviewed:
Michael Martin, Atheism, Morality and Meaning , 2002, Prometheus Books, 330pp, price £21.00 pb.     

Alcohol-Induced Amnesia and Personalized Drinking Feedback: Blackouts Predict Intervention Response

Alcohol-induced amnesia (“blackout”) is a reliable predictor of alcohol-related harm. Given its association with other negative consequences, experience of alcohol-induced amnesia may serve as a teachable moment, after which individuals are more likely to respond to intervention. To test this hypothesis, alcohol-induced amnesia was evaluated as a moderator of brief intervention effect on (a) alcohol-related consequences and (b) the proposed intervention mediators, protective behavioral strategies and peak blood alcohol concentration (BAC). Baseline alcohol risk measured using the Alcohol Use Disorders Identification Test (AUDIT) was also evaluated as a moderator to rule out the possibility that amnesia is simply an indicator of more general alcohol risk. College students (N = 198) reporting alcohol use in a typical week completed assessments at baseline and 1-month follow-up as part of a larger intervention trial. Participants were randomized to assessment only (AO; n = 58) or personalized feedback intervention (PFI; n = 140). Hierarchical regression was used to examine direct and indirect intervention effects. A significant group-by-amnesia interaction revealed that only PFI participants who had experienced alcohol-induced amnesia in the past month reported decreases in alcohol consequences at 1-month follow-up. The PFI reduced alcohol-related consequences indirectly through changes in peak BAC, but only among those who had experienced amnesia at baseline. In contrast, baseline alcohol risk (AUDIT) did not moderate intervention effects, and use of protective behavioral strategies did not statistically mediate intervention effects. Findings suggest that loss of memory for drinking events is a unique determinant of young adult response to brief alcohol intervention. Normative feedback interventions may be particularly effective for individuals who have experienced alcohol-induced amnesia in the past 30 days.     

Children’s multiplicative transformations of discrete and continuous quantities

Recent studies have documented an evolutionarily primitive, early emerging cognitive system for the mental representation of numerical quantity (the analog magnitude system). Studies with nonhuman primates, human infants, and preschoolers have shown this system to support computations of numerical ordering, addition, and subtraction involving whole number concepts prior to arithmetic training. Here we report evidence that this system supports children’s predictions about the outcomes of halving and perhaps also doubling transformations. A total of 138 kindergartners and first graders were asked to reason about the quantity resulting from the doubling or halving of an initial numerosity (of a set of dots) or an initial length (of a bar). Controls for dot size, total dot area, and dot density ensured that children were responding to the number of dots in the arrays. Prior to formal instruction in symbolic multiplication, division, or rational number, halving (and perhaps doubling) computations appear to be deployed over discrete and possibly continuous quantities. The ability to apply simple multiplicative transformations to analog magnitude representations of quantity may form a part of the toolkit that children use to construct later concepts of rational number.     

Bad riddance or good rubbish? Ownership and not loss aversion causes the endowment effect

People typically demand more to relinquish the goods they own than they would be willing to pay to acquire those goods if they did not already own them (the endowment effect). The standard economic explanation of this phenomenon is that people expect the pain of relinquishing a good to be greater than the pleasure of acquiring it (the loss aversion account). The standard psychological explanation is that people are reluctant to relinquish the goods they own simply because they associate those goods with themselves and not because they expect relinquishing them to be especially painful (the ownership account). Because sellers are usually owners, loss aversion and ownership have been confounded in previous studies of the endowment effect. In two experiments that deconfounded them, ownership produced an endowment effect but loss aversion did not. In Experiment 1, buyers were willing to pay just as much for a coffee mug as sellers demanded if the buyers already happened to own an identical mug. In Experiment 2, buyers’ brokers and sellers’ brokers agreed on the price of a mug, but both brokers traded at higher prices when they happened to own mugs that were identical to the ones they were trading. In short, the endowment effect disappeared when buyers were owners and when sellers were not, suggesting that ownership and not loss aversion causes the endowment effect in the standard experimental paradigm.     

Genetic influences on the development of spatial skills during early adolescence

The course of development of skill at face encoding is disrupted in early adolescence. Evidence is provided that the timing of this disruption is under genetic control. Regardless of their age, girls in the midst of pubertal change encode faces less efficiently than prepubescent or postpubescent controls. This maturational influence on face encoding is contrasted with a different effect of pubertal development on another visuo-spatial ability, performance on the Embedded Figures Test (EFT). Regardless of their pubertal status at time of testing, girls who mature earlier are disadvantaged on EFT compared to those who mature later. The results for EFT replicate earlier findings on the relation between individual differences in the age at which adolescence begins and certain spatial skills. Several possible explanations for each of these effects—that of maturational status on face encoding and that of maturation rate on EFT—are discussed. Consideration of the relation between physical and mental growth is advocated as a source of constraints on explanations of cognitive development.     

POSITIVE PRACTICE OVERCORRECTION: THE EFFECTS OF DURATION OF POSITIVE PRACTICE ON ACQUISITION AND RESPONSE REDUCTION

The effects of long and short durations of positive practice overcorrection were studied, for reduction of off-task behavior after an instruction to perform an object-placement task. Off-task behavior, correct responses, and approximate responses were all observed. Off-task behavior received positive practice. The short and long practice durations (30 seconds and 3 minutes) produced equally rapid reduction of off-task behavior and acquisition of correct object-placement performance. Over sessions, much less time was required for positive practice when the short practice duration was used. Approximate responses, which also avoided positive practice, occurred at low rates relative to correct responding. Negative side effects were observed to occur primarily during sessions with long positive practice. These results indicate that use of short durations of positive practice can reduce the practice time required and negative side effects, with no loss of training effectiveness either for reducing inappropriate behavior or increasing a desired alternative behavior.     

Effects of d- versus l-amphetamine, food deprivation, and current intensity on self-stimulation of the lateral hypothalamus, substantia nigra, and medial frontal cortex of the rat.

Intracranial sefl-stimulation (ICSS) was studied in rats with chronically implanted lateral hypothalamic, substantia nigra, or medial frontal cortex bipolar electrodes. A comparison of the effects of d- and l-amphetamine on ICSS response rate indicated that the d isomer had a greater facilitatory effect than the l isomer at lateral hypothalamic and substantia nigra electrode sites but that neither isomer significantly affected medial frontal cortex ICSS. d-Amphetamine resulted in a dose-related increase in motor activity, but the same doses of the l isomer resulted in decreased motor activity. Only lateral hypothalamic ICSS response rates increased significantly in response to food deprivation. Increases in current intensity above the level used for amphetamine and food-deprivation testing facilitated lateral hypothalamic and substantia nigra ICSS response rates but did not significantly affect medial frontal cortex response rates. The responsiveness of ICSS at each electrode site appeared to be correlated with the fiber- and cell-body densities of catecholaminergic systems in the brain.     

Anatomy of a stimulus domain: The relation between multidimensional and unidimensional scaling of noise bands

Theoretically, there are many possible relationships between multidimensional scaling and unidimensional scalings of the same stimulus domain. In particular, it is uncertain what will happen if the number of psychological “dimensions” exceeds the number of physical variables. The multidimensional scaling of noise bands, unidimensionally a relatively well-understood domain, was done to explore these problems. In correspondence with the number of physical variables, a two-dimensional configuration was found to give a satisfactory account of the judgments of magnitude of stimulus difference. Axes of loudness, volume, and density were found to fit the configuration with a high degree of precision, lending support to the metric value of numbers produced in magnitude estimation. Pitch, or frequency, also had a simple relationship to the configuration, but was not an axis or dimension. Therefore, the usual conceptualization of judgments of overall similarity as the result of combining difference on separate dimensions is questioned. It is suggested that multidimensional configurations may sometimes correspond to internal representations of general importance.