Facial resemblance of Japanese children to their parents

Facial resemblance between parents and their children could be an indicator of genetic relationship, and selective pressure could bias the resemblance of appearance. We assessed the degree of resemblance of 38 Japanese children (3–6 years old) to each of their parents using photographs. We asked nonrelatives to assess which of the parents each child resembled, manipulating indications of the sex of the children. Variance in the degree of resemblance between the children and their fathers was very large. Although the basic facial appearance of each parent can be reflected in each child with 50% probability, the children did not equally show the facial characteristics of each parent at the individual level. The indication of sex had no significant effect on the assessment of resemblance. On the other hand, a questionnaire given to the assessors revealed that, as children, they tended to be said to resemble the opposite-sex parent. This result indicates that alleged resemblance does not reflect an actual condition but rather might have cultural meaning. Electronic Publication     

Facial resemblance between women's partners and brothers

Research on optimal outbreeding describes the greater reproductive success experienced on average by couples who are neither too closely related, nor too genetically dissimilar. How is optimal outbreeding achieved? Faces that subtly resemble family members could present useful cues to a potential reproductive partner with an optimal level of genetic dissimilarity. Here, we present the first empirical data that heterosexual women select partners who resemble their brothers. Raters ranked the facial similarity between a woman's male partner, and that woman's brother compared to foils. In a multilevel ordinal logistic regression that modeled variability in both the stimuli and the raters, there was clear evidence for perceptual similarity in facial photographs of a woman's partner and her brother. That is, although siblings themselves are sexually aversive, sibling resemblance is not. The affective responses of disgust and attraction may be calibrated to distinguish close kin from individuals with some genetic dissimilarity during partner choice.     

Facial resemblance increases the attractiveness of same-sex faces more than other-sex faces

Our reactions to facial self-resemblance could reflect either specialized responses to cues of kinship or by-products of the general perceptual mechanisms of face encoding and mere exposure. The adaptive hypothesis predicts differences in reactions to self-resemblance in mating and prosocial contexts, while the by-product hypothesis does not. Using face images that were digitally transformed to resemble participants, I showed that the effects of resemblance on attractiveness judgements depended on both the sex of the judge and the sex of the face being judged: facial resemblance increased attractiveness judgements of same-sex faces more than other-sex faces, despite the use of identical procedures to manipulate resemblance. A control experiment indicated these effects were caused neither by lower resemblance of other-sex faces than same-sex faces, nor by an increased perception of averageness or familiarity of same-sex faces due to prototyping or mere exposure affecting only same-sex faces. The differential impact of self-resemblance on our perception of same-sex and other-sex faces supports the hypothesis that humans use facial resemblance as a cue of kinship.     

Familial resemblance for immunoglobulin levels

The familial resemblance for immunoglobulin A, D, E, G, and M levels was investigated with family data collected in Canada and the U.S., entertaining both multifactorial and single gene hypotheses. Significant familial effects were found for each of the immunoglobulins, and there was significant support for a major gene hypothesis for IgA and IgD levels. Whereas there have been several reports suggesting a major gene determinant for IgE levels, including that from our own Canadian study, analysis of the U.S. sample suggested that a multifactorial component parsimoniously explained the observed familial resemblance.     

Residual family resemblance for PTC taste sensitivity

Summary Complex segregation analysis reveals no evidence for incomplete dominance, polygenic variation, or an effect of family environment on PTC sensitivity. Estimates of gene frequency and displacement from a phenotypic trichotomy agree closely with conventional values for the dichotomy of tasters vs. nontasters.     

Graphical comparison of resemblance measures in phytosociology

A simple graphical method, COREM, is described for the comparison of quantitative resemblance measures. The basis of the method is the ordered comparison case series (OCCAS) composed of relevé pairs ranked in decreasing order of similarity. For a given OCCAS, values of given resemblance functions are calculated and plotted in COREM.Delta resemblance (DR) is defined as the rate of change between two neighbouring relevé pairs in the OCCAS. High mean delta resemblance (% MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqaqpepeea0xe9qqVa0l% b9peea0lb9sq-JfrVkFHe9peea0dXdarVe0Fb9pgea0xa9pue9Fve9% Ffc8meGabaqaciGacaGaaeqabaWaaeaaeaaakeaadaqdaaqaaGqaai% aa-reacaWFsbaaaaaa!392E!\[\overline DR \]) of a resemblance measure indicates a high power of resolution and small standard deviation (SDDR) is indicative of linearity. A measure of efficiency combines % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqaqpepeea0xe9qqVa0l% b9peea0lb9sq-JfrVkFHe9peea0dXdarVe0Fb9pgea0xa9pue9Fve9% Ffc8meGabaqaciGacaGaaeqabaWaaeaaeaaakeaadaqdaaqaaGqaai% aa-reacaWFsbaaaaaa!392E!\[\overline DR \] and SDDR in the coefficient of variation for delta resemblance (CVDR). An efficient measure shows balanced sensitivity to the common and differential species. With the method COREM locally optimal resemblance measures may be selected for any given set of relevés which produce the sharpest separation of clusters. A reasonable compromise is to use types of measures, such as the similarity ratio (SIM6), Czekanowski coefficient (SIM8), or floristic similarity (SIM9), which have the best chance of being successful in most relevé sets. A study of transformation functions on Braun-Blanquet values with the help of COREM demonstrates that the combined transformation is the most advantageous for clustering. It is shown that standardization by relevés, or conversion to unit sum has undesirable effects.During the preparation of this paper the author was a recipient of a Postgraduate Scholarship, Deutscher Akademischer Austauschdients, Dortmund, KFA Abteilung Algenforschung, Germany. The author would like to thank L. Orlóci, P. Juhász-Nagy and E. van der Maarel for valuable suggestions, and comments.