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

Emergenesis: Genetic traits that may not run in familes.

Traits that are influenced by a configuration--rather than by a simple sum-- of polymorphic genes may not be seen to be genetic unless one studies monozygotic twins (who share all their genes and thus all gene configurations) because such “emergenic” traits will tend not to run in families. Personal idiosyncrasies that have been found to be surprisingly concordant among MZ twins separated in infancy and reared apart may be emergenic traits. More speculatively, important human traits like leadership, genius in its many manfestations, being an eflective therapist or parent, as well as certain psychopathological syndromes, may also be emergenic. These ideas re-emphasize the importance of the role played in human aflairs by genetic variation

Construction and validation of the SON-R 5 1/2-17, the Snijders-Oomen non-verbal intelligence test

In this thesis the construction and validation of the SON-R 5,5-17 is described, the recent revision of the Snijders-Oomen non-verbal intelligence test. The SON-R is an individual test of (non-verbal) intelligence for children in the ages of 51/2 to 17 years. The test was published in 1989 with an extensive 'Manual and researchr eport' in English, German and Dutch. The thesis is for the greater part a reprint of the 'Manual and research report' with the omission of norm tablesa nd instructionsf or practical use of the test and with the addition of some new parts. ... Zie: Summar

Relativistic analysis of magnetoelectric crystals: extracting a new 4-dimensional P odd and T odd pseudoscalar from Cr_2 O_3 data

Earlier, the linear magnetoelectric effect of chromium sesquioxide Cr_2 O_3 has been determined experimentally as a function of temperature. One measures the electric field-induced magnetization on Cr_2 O_3 crystals or the magnetic field-induced polarization. From the magnetoelectric moduli of Cr_2 O_3 we extract a 4-dimensional relativistic invariant pseudoscalar \tilde\alpha. It is temperature dependent and of the order of ~ 10^{-4} Y_0, with Y_0 as vacuum admittance. We show that the new pseudoscalar \tilde\alpha is odd under parity transformation and odd under time inversion. Moreover, \tilde\alpha is for Cr_2 O_3 what Tellegen's gyrator is for two port theory, the axion field for axion electrodynamics, and the PEMC (perfect electromagnetic conductor) for electrical engineering.Comment: 6 pages latex, 3 figures, accepted by Physics Letters