Common genetic effects on risk-taking preferences and choices

Although prior research has shown that risk-taking preferences and choices are correlated across many domains, there is a dearth of research investigating whether these correlations are primarily the result of genetic or environmental factors. We examine the extent to which common genetic factors account for the association between general risk-taking preferences and domain specific risk-taking preferences, and between general risk-taking preferences and risk taking choices in financial investments, stock market participation and business formation. Using data from 1898 monozygotic (MZ) and 1344 same-sex dizygotic (DZ) twins, we find that general risk-taking shares a common genetic component with domain-specific risk-taking preferences and risk-taking choices

A Neglected Route to Realism About Quantum Mechanics

Bell's Theorem assumes that hidden variables are not influenced by future measurement settings. The assumption has sometimes been questioned, but the suggestion has been thought outlandish, even by the taxed standards of the discipline. (Bell thought that it led to fatalism.) The case for this reaction turns out to be surprisingly weak, however. We show that QM easily evades the standard objections to advanced action. And the approach has striking advantages, especially in avoiding the apparent conflict between Bell's Theorem and special relativity. The second part of the paper considers the broader question as to why advanced action seems so counterintuitive. We investigate the origins of our ordinary intuitions about causal asymmetry. It is argued that the view that the past does not depend on the future is largely anthropocentric, a kind of projection of our own temporal asymmetry. Many physicists have also reached this conclusion, but have thought that if causation has no objective direction, there is no objective content to an advanced action interpretation of QM. This turns out to be a mistake. From the ordinary subjective perspective, we can distinguish two sorts of objective world: one "looks as if" it contains only forward causation, the other ``looks as if'' it involves a mix of backward and forward causation. This clarifies the objective core of an advanced action interpretation of QM, and shows that there is an independent symmetry argument in favour of the approach.Comment: 35 pages, LaTex (forthcoming in MIND, July 1994; written for a philosophical audience, but perhaps of some interest here

Is humn mating adventitious or the result of lawful choice? A twin study of mate selection.

Inventory data on a large sample of middle-aged twins and their spouses confirmed that spousal pairs are consistently but weakly similar on traits of personality, interests, talents, and attitudes. We argue, however, that neither the Similarity model of mate selection, nor one of its facets, the Equity model, can account for specific mate choice. We therefore tested the hypothesis that people select their mates using idiosyncratic criteria and that the spouses of monozygotic (MZ) twins should therefore be very similar. When compared to spouses of dizygotic (DZ) twins or even to random pairs of spouses, the spouses of MZ twins failed to show the predicted excess of small intra-spouse differences. We asked 547 of these twins to rate their attitudes toward their cotwin's choices of wardrobe, furnishings, vacations, jobs - and spouses; a similar questionnaire was completed by the spouses of these twins. Both data sets confirm that MZ twins are very similar in most of their choices, more so than DZ twins, but nearly 40% of both MZs and DZs recall that they actually disliked their cotwin's choice of mate at the time that choice was made. Similarly, 30% of the spouses of MZ twins report actually disliking the identical twin of the mate they had recently selected. Our findings suggest that characteristics both of the chooser and the chosen constrain mate selection only weakly. We propose that it is romantic infatuation that commonly determines the final choice from a broad field of potential eligibles and that this phenomenon is inherently random, in the same sense as is imprinting in precocial birds

Beings in their own right? Exploring Children and young people's sibling and twin relationships in the Minority World

This paper examines the contributions that the sociological study of sibship and twinship in the Minority World can make to childhood studies. It argues that, in providing one forum within which to explore children and young people's social relationships, we can add to our understanding of children and young people's interdependence and develop a more nuanced understanding of agency. As emergent subjects, children, young people and adults are in a process of ‘becoming’. However, this does not mean that they can ‘become’ anything they choose to. The notion of negotiated interdependence (Punch 2002) is useful in helping us to grasp the contingent nature of children and young people's agency

Improving Cosmological Distance Measurements Using Twin Type Ia Supernovae

We introduce a method for identifying "twin" Type Ia supernovae, and using them to improve distance measurements. This novel approach to Type Ia supernova standardization is made possible by spectrophotometric time series observations from the Nearby Supernova Factory (SNfactory). We begin with a well-measured set of supernovae, find pairs whose spectra match well across the entire optical window, and then test whether this leads to a smaller dispersion in their absolute brightnesses. This analysis is completed in a blinded fashion, ensuring that decisions made in implementing the method do not inadvertently bias the result. We find that pairs of supernovae with more closely matched spectra indeed have reduced brightness dispersion. We are able to standardize this initial set of SNfactory supernovae to 0.083 +/- 0.012 magnitudes, implying a dispersion of 0.072 +/- 0.010 magnitudes in the absence of peculiar velocities. We estimate that with larger numbers of comparison SNe, e.g, using the final SNfactory spectrophotometric dataset as a reference, this method will be capable of standardizing high-redshift supernovae to within 0.06-0.07 magnitudes. These results imply that at least 3/4 of the variance in Hubble residuals in current supernova cosmology analyses is due to previously unaccounted-for astrophysical differences among the supernovaeComment: 37 pages, 9 figures, 5 tables. Accepted for publication in ApJ. Fixed typo in arXiv abstrac

Beyond foraging: behavioral science and the future of institutional economics

Institutions affect economic outcomes, but variation in them cannot be directly linked to environmental factors such as geography, climate, or technological availabilities. Game theoretic approaches, based as they typically are on foraging only assumptions, do not provide an adequate foundation for understanding the intervening role of politics and ideology; nor does the view that culture and institutions are entirely socially constructed. Understanding what institutions are and how they influence behavior requires an approach that is in part biological, focusing on cognitive and behavioral adaptations for social interaction favored in the past by group selection. These adaptations, along with their effects on canalizing social learning, help to explain uniformities in political and social order, and are the bedrock upon which we build cultural and institutional variability

To Be or not to Be? A Critical Appraisal of the Welfare of Children Conceived through New Reproductive Technologies

Over three million children are believed to have been born worldwide - and over 200,000 annually - as a result of “new reproductive technologies” (NRTs). This paper provides a critical review of the proposition that children are always best-served by being born. Drawing on the specific examples of intracytoplasmic sperm injection (ICSI); multiple births; pre-implantation genetic diagnosis (PGD) and selecting the characteristics of children, and donor conception it argues that there are defensible welfare arguments for curtailing unrestricted access to NRTs. Increased and wider dialogue is proposed to encourage the implementation of practices and policies that take account of the interests of all those affected by NRTs and which command public support