Tamás Bereczkei

Sexual imprinting in human mate choice

Animal and human studies have shown that individuals choose mates partly on the basis of similarity, a tendency referred to as homogamy. Several authors have suggested that a specific innate recognition mechanism, phenotypic matching, allows the organism to detect similar others by their resemblance to itself. However, several objections have been raised to this theory on both empirical and theoretical grounds. Here, we report that homogamy in humans is attained partly by sexual imprinting on the opposite–sex parent during childhood. We hypothesized that children fashion a mental model of their opposite–sex parents phenotype that is used as a template for acquiring mates. To disentangle the effects of phenotypic matching and sexual imprinting, adopted daughters and their rearing families were examined. Judges found significant resemblance on facial traits between daughters husband and her adoptive father. Furthermore, this effect may be modified by the quality of the father–daughter relationship during childhood. Daughters who received more emotional support from their adoptive father were more likely to choose mates similar to the father than those whose father provided a less positive emotional atmosphere.

Homogamy, genetic similarity, and imprinting; parental influence on mate choice preferences

Abstract Whereas the hypothesis of genetically mediated homogamy has been supported by several studies, certain theoretical and methodological criticisms have been raised against genetic similarity theory. As an alternative approach to assortative mating, we suppose that imprinting-like mechanisms, rather than “direct” genetic detection, are responsible for choosing similar spouses. In a study aimed at comparing more than 300 facial photographs of family members and controls, the judges correctly matched wives to their mother-in-law at a significantly higher rate than expected by chance. Furthermore, a higher degree of similarity was ascribed between the husbands’ mother and the husbands’ wife than between the husbands and their wives. A regression analysis has revealed that men who had been more frequently rejected by their mother during childhood were less likely to choose mates who resemble their mothers in physical appearance. These results suggest that under the influence of childhood experiences, sons internalize their mother’s phenotype as a template for acquiring similar mates.

Mate choice marital success and reproduction in a modern society.

Abstract A series of eight predictions concerning human mating was tested on interviews with 1057 female and 774 male Hungarians, who were close to completed fertility. Mating preferences as predicted from the evolutionary explanations are reflected in actual mate choice. Males, more than females, prefer and choose younger mates at marriage, whereas females tend to marry higher educated mates. The reproductive consequences of mate choice are adaptive: females who marry higher status mates and males who choose younger mates have significantly more surviving children than those following alternative mating strategies. This link between mating preferences and reproductive output may be mediated by marital success as a proximate mechanism. Couples whose wives are younger and/or less educated and whose husbands are older and/or more educated stay together for a longer period of time than other couples. Similarly, the age and educational differences between spouses are associated with marriage quality. Finally, homogamy is found as a widespread form of mate choice that proved to be almost as reproductively successful a strategy as hypergamy. We argue that females switch between homogamy and hypergamy and vice versa, depending on the particular social circumstance.

Evolutionary pathway of child development

An evolutionary theory of socialization suggests that children from father-absent families will mature earlier, and form less-stable pair bonds, compared with those from father-present families. Using a sample of about 1,000 persons the recent study focuses on elements of father-absent children’s behavior that could be better explained by a Darwinian approach than by rival social science theories. As a result of their enhanced interest in male competition, father-absent boys were found to engage in rule-breaking behavior more intensively than father-present boys. Compared with father-present children, adolescents from widowed households (both boys and girls) showed a higher intensity of various kinds of noncompliant behavior, which can be linked to their earlier maturation. School attendance, age at marriage, and marital success proved to be influenced by the children’s early family experiences, governed by adapted evolutionary strategies. Father-absent daughters conceived more children than those whose fathers were present during their childhood. As evolutionary theory predicts, reproductive behavior of individuals from divorced households differed from that of individuals who grew up in widowed households. Finally, the strong correlation found between spontaneous abortion/stillbirths and family arrangement indicates that father absence has certain direct impacts on the neurohormonal processes of child development.

The ratio of the 2nd to 4th finger length predicts spatial ability in men but not women

On average men score higher on time-constrained tests of spatial ability than women. Both brain and behaviour are influenced by prenatal and adult exposure to gonadal steroid hormones. In humans the ratio of the 2nd to 4th finger length (2D:4D) is a sexually dimorphic character that is lower in men than women and negatively correlated with testosterone levels. We report three independent studies from Sweden/London, Hungary and Liverpool confirming that 2D:4D is generally larger in women than men, that men obtain higher MRT scores than women, and demonstrating that 2D:4D is negatively correlated with MRT score in men but not women. We argue that this negative correlation between 2D:4D and spatial ability reflects the association between 2D:4D and prenatal, rather than adult, exposure to testosterone and conclude that testosterone exposure influences brain development leading to better performance on male-favouring spatial tasks.

Hairstyle as an adaptive means of displaying phenotypic quality.

Although facial features that are considered beautiful have been investigated across cultures using the framework of sexual selection theory, the effects of head hair on esthetic evaluations have rarely been examined from an evolutionary perspective. In the present study the effects of six hair-styles (short, medium-length, long, disheveled, knot [hair bun], unkempt) on female facial attractiveness were examined in four dimensions (femininity, youth, health, sexiness) relative to faces without visible head hair (“basic face”). Three evolutionary hypotheses were tested (covering hypothesis, healthy mate theory, and good genes model); only the good genes model was supported by our data. According to this theory, individuals who can afford the high costs of long hair are those who have good phenotypic and genetic quality. In accordance with this hypothesis, we found that only long and medium-length hair had a significant positive effect on ratings of women’s attractiveness; the other hairstyles did not influence the evaluation of their physical beauty. Furthermore, these two hairstyles caused a much larger change in the dimension of health than in the rest of the dimensions. Finally, male raters considered the longer-haired female subjects’ health status better, especially if the subjects were less attractive women. The possible relationships between facial attractiveness and hair are discussed, and alternative explanations are presented.

Stressful family environment, mortality, and child socialisation: Life-history strategies among adolescents and adults from unfavourable social circumstances:

This study, based on questionnaires given to 732 subjects, uses an integrative approach with a focus on evolutionary (life-history) explanations. In accordance with Belsky, Steinberg, and Draper’s theoretical model of socialisation (1991), we claim that experiences during childhood trigger variations in the life cycle and shift developmental trajectories as adaptive answers to different environmental conditions. Unfavourable family conditions constitute an unpredictable and unstable environment that make children susceptible to adopting opportunistic mating strategies rather than parenting strategies. Based on Chisholm’s statement (1993) that high stress in the family provides cues for local death rates, we argue that mortality rates may have a significant effect on reproductive decisions, even in post-industrial societies. We report that length of schooling, date of the ” rst marriage, and fertility were associated with the subjects’ family conditions, such as parental affirmation, emotional atmosphere, parent-subject conflicts, and parental relations. Women growing up in unfavourable family circumstances ”nish schooling and marry earlier, and this shift in developmental trajectory is likely to lead to the higher number of children measured among these women. Men, on the other hand, do not show such a difference in reproductive output, which may be due to their increased involvement in sexual competition. Remarkably, significant correlation has been found between life-history strategy and mortality rates; those coming from unfavourable environments have more deceased sisters and brothers than others. It is possible that individual differences in mating and parenting behaviour are still contingent, among others, on local death rates.

Machiavellianism and adult attachment in general interpersonal relationships and close relationships

Up to the present, the relationship between Machiavellianism and adult attachment has remained a question to be answered in the psychological literature. That is why this study focused on the relationship between Machiavellianism and attachment towards significant others in general interpersonal relationships and in intimate-close relationships. Two attachment tests (Relationship Questionnaire and long-form of Experiences in Close Relationship) and the Mach-IV test were conducted on a sample consisting of 185 subjects. Results have revealed that Machiavellian subjects show a dismissing-avoidant attachment style in their general interpersonal relationships, while avoidance is further accompanied by some characteristics of attachment anxiety in their intimate-close relationships. Our findings further refine the relationship between Machiavellianism and dismissing-avoidant attachment. Machiavellian individuals not only have a negative representation of significant others, but they also tend to seek symbiotic closeness in order to exploit their partners. This ambitendency in distance regulation might be particularly important in understanding the vulnerability of Machiavellian individuals.

Low birth weight, maternal birth-spacing decisions, and future reproduction : A cost-benefit analysis.

The aim of this study is an analysis of the possible adaptive consequences of delivery of low birth weight infants. We attempt to reveal the cost and benefit components of bearing small children, estimate the chance of the infants’ survival, and calculate the mothers’ reproductive success. According to life-history theory, under certain circumstances mothers can enhance their lifetime fitness by lowering the rate of investment in an infant and/or enhancing the rate of subsequent births. We assume that living in a risky environment and giving birth to a small infant may involve a shift from qualitative to quantitative production of offspring. Given high infant mortality rates, parents will have a reproductive interest in producing a relatively large number of children with a smaller amount of prenatal investment. This hypothesis was tested among 650 Gypsy and 717 non-Gypsy Hungarian mothers. Our study has revealed that 23.8% of the Gypsy mothers had low birth weight (<2,500 g) children, whose mortality rate is very high. These mothers also had more spontaneous abortions and stillbirths than those with normal weight children. As a possible response to these reproductive failures, they shortened birth spacing, gaining 2–4 years across their reproductive lifespan for having additional children. Because of the relatively short interbirth intervals, by the end of their fertility period, Gypsy mothers with one or two low birth weight infants have significantly more children than their ethnic Hungarian counterparts. They appear to compensate for handicaps associated with low birth weights by having a larger number of closely spaced children following the birth of one or more infants with a reduced probability of survival. The possible alternative explanations are discussed, and the long-term reproductive benefits are estimated for both ethnic groups.

Preference for Facial Self-Resemblance and Attractiveness in Human Mate Choice

Empirical studies present considerably consistent data about human mate choice, from which we may infer that it tends to be homogamous for various traits. However, different experiments on facial resemblance led to contradictory results. To obtain additional data about the preference for self-resembling potential mates, male and female composite faces were modified in a manner to resemble subjects. Volunteers were asked to choose a potential partner from three images in different situations: self-resembling faces, non-resembling faces (both with the same degree of other-rated attractiveness), and images which were rated by others as more attractive than the self-resembling faces. Women did not show any preference for similarity; they preferred the most attractive male and female faces. In contrast, men preferred the most attractive images of the opposite sex to self-resembling faces and the self-resembling to non-resembling faces. The self-resemblance of same-sex faces was preferred by neither men nor women. Our results support the hypothesis that both facial similarity (i.e., cues of shared genes) and observer-independent features of attractiveness (i.e., honest signals of genetic quality) play an important role in males’ mate choice. The lack of choice for self-resemblance on the female side in this particular study might reflect their more complex decision-making rules that are probably based on other cues beside visual stimuli.