A note on changes in age at marriage of females and their effect on the birth rate in India

Abstract

Epidemiologists contend that income inequality reduces the health and life expectancy of the whole population, but this argument does not make sense within its own evolutionary framework. Recent evolutionary psychological theory suggests that the human brain, adapted to the ancestral environment, has difficulty comprehending and dealing with entities and situations that did not exist in the ancestral environment, and that general intelligence evolved as a domain‐specific adaptation to solve evolutionarily novel problems. Since most dangers to health in the contemporary society are evolutionarily novel, it follows that more intelligent individuals are better able to recognize and deal with such dangers and live longer. Consistent with the theory, and replicating an earlier study of cross‐national data, income inequality has no effect on the health and longevity of the population across the American states, when the racial composition (percent black) is controlled, but the average intelligence of the population (state IQ) has a significant effect The data presented here and in the earlier study challenge the conclusion that income inequality reduces the health of the population.     

Mate preferences and choices for facial and body hair in heterosexual women and homosexual men: influence of sex,population, homogamy,and imprinting-like effect

Recent research has reported that male body and facial hair influence women's mate preferences. However, it is not clear whether such preferences are typical for women or for individuals who prefer males as sexual partners. Here we explored body and facial hair in preferred and actual partners among men and women who prefer men as sexual partners. Including homosexual individuals provides a unique opportunity to investigate whether evolved mating psychologies are specific to the sex of the individual or sex of the partner. Based on an online survey of 1577 participants from Brazil and the Czech Republic, we found that, on average, homosexual men preferred hairier stimuli than heterosexual women, supporting past findings that homosexual men have strong preferences for masculine traits. Preferences for facial and body hair appear to be influenced less by sex of the preferred partner than sex of the individual, pointing to a possible sex-specific mating psychology. Further, Brazilians preferred bigger beards than Czechs, which was positively associated with the self-reported amount of beardedness in Brazil, suggesting that familiarity effects underpin cross-cultural differences in preferences for facial hair. Moreover, homosexual men preferred a self-similar degree of beardedness, and Czech women preferred a similar degree of beardedness as their fathers had during their childhood. However, these effects were not associated with the level of facial hair in their actual partners; in general, mate preferences and actual mate choices for facial and body hair differed. Thus, individual differences in some self-reported characteristics, cultural factors, and aspects of personal experience may modulate differences in preferences for masculine traits.     

A comparison of heterosexual and homosexual mating preferences in personal advertisements

Human heterosexual mating preferences have been shown to conform to predictions drawn from evolutionary theory, with men and women adopting broadly distinct strategies. Attempts to reconcile sexual selection theory with homosexual behavior have been less consistent, however, and have largely focussed on addressing two alternative perspectives: (i) that gay men and lesbians display phenotypic traits in common with opposite sex heterosexual individuals or (ii) that homosexual individuals display sex-typical, or exaggerated sex-typical phenotypes. Testing these hypotheses is complicated by sampling issues involved in the study of human sexual orientation, since obtaining standardized and comparable samples of heterosexual and non-heterosexual mating preferences is a prerequisite to analysis. Here we present a comparison of homosexual and heterosexual mating strategies in men and women using a sample of 1733 personal (‘lonely hearts’) adverts gathered from a single source. We used principal components analysis in order to expose underlying structure of the advertisements, and identify three components involving relative emphasis placed on resources, physical attractiveness and personality when offering or seeking mate characteristics. While homosexual individuals are shown to resemble their own-sex heterosexual counterparts in terms of emphasis placed on partner physical attractiveness relative to partner personality, no clear pattern emerges in other aspects of advertisement strategy. Nevertheless, there we find no evidence in support of the hypothesis that homosexual men and women are intrinsically opposite-sex typical in terms of mate preferences.     

Migraine: Intelligence,Social Class,and Familial Prevalence

Groups of individuals with headache, unilateral headache, and migraine, and a fourth group who had not had a headache in the previous year, were identified by questionnaire from a random sample of adults in the general population. Intelligence and social class were assessed in about 400 individuals. There was no evidence that individuals with migraine were more intelligent or of higher social class. There was, however, a suggestion that the more intelligent individuals with migraine, and those in social classes I and II, were more likely to consult a doctor for their headaches. This trend might explain the origin of the hypotheses associating migraine with intelligence and with social class.Random samples of individuals with migraine with headache and without headache in the previous year were the probands for a family study. There were 524 first-degree relatives over 21 years of age who lived in South Wales. Headache histories, obtained “blindly” from over 99% of these relatives with a standard questionnaire, were classified as migraine, possible migraine, headache, or without headache in the previous year. The prevalence of migraine in the families of the migrainous probands was nearly twice as high as the prevalence in the other families, but this difference was not statistically significant. It is suggested that family history should not be included in the definition of migraine and that heredity is much less important in migraine than is usually supposed.     

The diversity and evolution of recruitment behaviour in ants,with a discussion of the usefulness of parsimony criteria in the reconstruction of evolutionary histories

Summary Three alternative hypotheses about the evolution of recruitment behaviour in ants, based on accounts in the literature, are compared by means of a cladistic analysis. The three hypotheses are the following:Hypothesis 1. Increasingly efficient recruitment behaviours exhibited by different ant species have been shaped by or are correlated with ant phylogeny.Hypothesis 2. Increasingly efficient recruitment behaviours represent necessary evolutionary steps independently followed during the evolution of different ant clades.Hypothesis 3. Differently efficient recruitment behaviours have been selected in a convergent way among different species by similar population/environmental constraints.In a first stage of the analysis, these hypotheses have been compared in terms of parsimony (i.e. in terms of tree length = TL) of alternative cladograms based on recruitment behaviour only. The analysis gave the following results: Hypothesis 1, TL = 4; Hypothesis 2, TL = 18; Hypothesis 3, TL = 11. At least in terms of parsimony, hence, Hypothesis 1 appears to be the best. This hypothesis, however, cannot be retained for its total lack of congruence with current views on ant phylogeny. Among the remaining two hypotheses, Hypothesis 3 is again much (ca. 40%) more parsimonious than Hypothesis 2, but the retention index for recruitment behaviour on the relative cladogram is 0.2 as compared with 0.7 for Hypothesis 2. Practically, this implies biologically very implausible behavioural evolution indicated by very improbable ancestors for the species included in the analysis. In the case of recruitment evolution the biological credibility of each hypothesis is inversely proportional to its parsimony.The three hypotheses on the evolution of recruitment behaviour are compared again taking into account the morphological and behavioural correlates of recruitment. The results confirm those obtained by simple cladistic analysis of behaviour alone, namely that an obligatory (i. e. neither reversible nor random) increase in recruitment efficiency has been repeatedly selected within different ant clades. Inclusion of the recruitment correlates allows, in addition, a more precise formulation of the implications of each hypothesis and a tentative test of two other alternatives deduced from the literature. Most papers dealing with recruitment assume this behaviour to be controlled by a single gland, while at least two experimental analyses show that more than one gland is likely to be involved as behavioural releaser. A cladistic approach allowed testing of the following two adaptational hypotheses: A) Synergic behavioural control by several glands, allowing shift of the dominant role from one gland to another. B) Single gland control, making improbable the replacement of one gland by another that performs the same function. The results of the analysis appear to favour alternative A slightly, though neither alternative results in implausible evolutionary paths.It is stressed that parsimony remains the sole decisional criterion when no other criteria are available but it can by no way be preferred to the slightest trace of biological common sense.     

Green plants as intelligent organisms

Intelligent behaviour, even in humans, is an aspect of complex adaptive behaviour that provides a capacity for problem solving. This article assesses whether plants have a capacity to solve problems and, therefore, could be classified as intelligent organisms. The complex molecular network that is found in every plant cell and underpins plant behaviour is described. The problems that many plants face and that need solution are briefly outlined, and some of the kinds of behaviour used to solve these problems are discussed. A simple way of comparing plant intelligence between two genotypes is illustrated and some of the objections raised against the idea of plant intelligence are considered but discarded. It is concluded that plants exhibit the simple forms of behaviour that neuroscientists describe as basic intelligence.     

Methods based on artificial intelligence,for controlling biotechnological processes. Monitoring of the concentration of dissolved oxygen (part III)

A real-time artificial intelligence method for controlling the concentration of dissolved oxygen is proposed. Two projection versions of algorithms are considered in this paper. The versions vary in structure of the intelligent agents. One of the agents represents an automaton of expedient behaviour, the structure of the other consists of two automata which behave expediently in a complicated random medium. The first algorithm holds a check on a trend of change in values. The second version of the algorithm takes into account both the trend of change in the values and the speed of change in the values. Simulation studies show that expedient behaviour of the automata in the random medium for the control of dissolved oxygen concentration can bring about a good performance.     

THE EVOLUTION OF MATE PREFERENCES FOR MULTIPLE SEXUAL ORNAMENTS

Males of many species use multiple sexual ornaments in their courtship display. We investigate the evolution of female sexual preferences for more than a single male trait by the handicap process. The handicap process assumes that ornaments are indicators of male quality, and a female benefits from mate choice by her offspring inheriting “good genes” that increase survival chances. A new handicap model is developed that allows equilibria to be given in terms of selection pressures, independent of genetic parameters. Multiple sexual preferences evolve if the overall cost of choice is not greatly increased by a female using additional male traits in her assessment of potential mates. However, only a single preference is evolutionarily stable if assessment of additional male traits greatly increases the overall cost of choice (more than expected by combining the cost of each preference independently). Any single preference can evolve, the outcome being determined by initial conditions. The evolution of one preference effectively blocks the evolution of others, even for traits that are better indicators of male quality. Comparison is made with sexual selection caused by Fisher's runaway process in which male traits are purely attractive characters. This shows that sexual preferences for multiple Fisher traits are likely to evolve alongside preference for a single handicap trait that indicates male quality. This is a general difference in the evolutionary outcome of these two causes of sexual selection.     

Intelligence and mate choice: intelligent men are always appealing

What role does a man's intelligence play in women's mate preferences? Selecting a more intelligent mate often provides women with better access to resources and parental investment for offspring. But this preference may also provide indirect genetic benefits in the form of having offspring who are in better physical condition, regardless of parental provisioning. Intelligence then may serve as both a cue of a mate's provisioning abilities and his overall heritable phenotypic quality. In the current study, we examined the role of a man's intelligence in women's long- and short-term mate preferences. We used a rigorous psychometric measure (men's WAIS scores) to assess intelligence (the first study to our knowledge), in addition to women's subjective ratings to predict mate appeal. We also examined the related trait of creativity, using women's ratings as a first step, to assess whether creativity could predict mate appeal, above and beyond intelligence. Finally, we examined whether preferences for intelligent and creative short-term mates shifted according to a woman's conception risk. Multilevel modeling was used to identify predictors of mate appeal. Study participants (204 women) assessed the long- and short-term mate appeal of videos of 15 men with known measures of intelligence performing verbal and physical tasks. Findings indicate that both intelligence and creativity independently predicted mate appeal across mating contexts, but no conception-risk effects were detected. We discuss implications of these findings for the role of intelligence and creativity in women's mate choices.     

Preferences for symmetry in human faces in two cultures: data from the UK and the Hadza, an isolated group of hunter-gatherers

Many studies show agreement within and between cultures for general judgements of facial attractiveness. Few studies, however, have examined the attractiveness of specific traits and few have examined preferences in hunter-gatherers. The current study examined preferences for symmetry in both the UK and the Hadza, a hunter-gatherer society of Tanzania. We found that symmetry was more attractive than asymmetry across both the cultures and was more strongly preferred by the Hadza than in the UK. The different ecological conditions may play a role in generating this difference. Such variation in preference may be adaptive if it reflects adaptation to local conditions. Symmetry is thought to indicate genetic quality, which may be more important among the Hadza with much higher mortality rates from birth onwards. Hadza men who were more often named as good hunters placed a greater value on symmetry in female faces. These results suggest that high quality Hadza men are more discriminating in their choice of faces. Hadza women had increased preferences for symmetry in men's faces when they were pregnant or nursing, perhaps due to their increased discrimination and sensitivity to foods and disease harmful to a foetus or nursing infant. These results imply that symmetry is an evolutionarily relevant trait and that variation in symmetry preference appears strategic both between cultures and within individuals of a single culture.     

Childhood intelligence and adult obesity

Objective: Recent studies conclude childhood intelligence has no direct effect on adult obesity net of education, but evolutionary psychological theories suggest otherwise. Design and Methods: A population (n = 17,419) of British babies has been followed since birth in 1958 in a prospectively longitudinal study. Childhood general intelligence is measured at 7, 11, and 16, and adult BMI and obesity are measured at 51. Results: Childhood general intelligence has a direct effect on adult BMI, obesity, and weight gain, net of education, earnings, mother's BMI, father's BMI, childhood social class, and sex. More intelligent children grow up to eat more healthy foods and exercise more frequently as adults. Conclusion: Childhood intelligence has a direct effect on adult obesity unmediated by education or earnings. General intelligence decreases BMI only in adulthood when individuals have complete control over what they eat.     

Inter-Mount Social Interactions During Heterosexual and Homosexual Consortships in Japanese Macaques

In this study, we examined whether female Japanese macaques ( Macaca fuscata ) exhibited male-typical patterns of inter-mount social behaviour during homosexual consortships. Data were collected on heterosexual and homosexual consortships from a population of free-ranging Japanese macaques in Arashiyama, Japan. Inter-mount intervals were defined as the period between two consecutive mounts. A total of 3374 heterosexual inter-mount intervals and 1412 homosexual inter-mount intervals were analysed. We examined nine different categories of inter-mount behaviour. Sex differences between heterosexually consorting males and females existed for three of the inter-mount behaviours we examined (i.e. ventral-to-dorsal orientation, aggression directed toward third party individuals, tree-shaking displays). The subordinate female partners in homosexually consorting pairs exhibited some sex-atypical inter-mount behaviours. This sex-atypicality did not appear to reflect generalized developmental canalization in the direction of a male-typical suite of behaviours. Rather, the observed behavioural sex-atypicality could be best explained in terms of the unique alliance-related dynamics that characterized homosexual consortships in Japanese macaques.     

Kleptoparasitic Melees��Modelling Food Stealing Featuring Contests with Multiple Individuals

Kleptoparasitism is the stealing of food by one animal from another. This has been modelled in various ways before, but all previous models have only allowed contests between two individuals. We investigate a model of kleptoparasitism where individuals are allowed to fight in groups of more than two, as often occurs in real populations. We find the equilibrium distribution of the population amongst various behavioural states, conditional upon the strategies played and environmental parameters, and then find evolutionarily stable challenging strategies. We find that there is always at least one ESS, but sometimes there are two or more, and discuss the circumstances when particular ESSs occur, and when there are likely to be multiple ESSs.     

Dominance hierarchies and factors influencing dominance in the guppy Poecilia reticulata (peters)

Dominance behaviour and factors influencing dominance were investigated in small heterosexual and homosexual groups of guppies (Poecilia reticulata) in the laboratory. Straight line nip-right hierarchies were the most frequent type of dominance relationship. In heterosexual groups separate homosexual hierarchies were formed, and females were the more dominant sex. Dominant males performed significantly more reproductive behaviour than lower rank individuals. Agonistic behaviour appears early in young P. reticulata. Factors involved in determining dominance were size, sex and aggressiveness. Individual or role recognition or both may occur in this species. Advantages of dominance are discussed.     

Intelligence can be detected but is not found attractive in videos and live interactions

Self-reported mate preferences suggest intelligence is valued across cultures, consistent with the idea that human intelligence evolved as a sexually selected trait. The validity of self-reports has been questioned though, so it remains unclear whether objectively assessed intelligence is indeed attractive. In Study 1, 88 target men had their intelligence measured and based on short video clips were rated on intelligence, funniness, physical attractiveness and mate appeal by 179 women. In Study 2 (N = 763), participants took part in 2 to 5 speed-dating sessions in which their intelligence was measured and they rated each other's intelligence, funniness, and mate appeal. Measured intelligence did not predict increased mate appeal in either study, whereas perceived intelligence and funniness did. More intelligent people were perceived as more intelligent, but not as funnier. Results suggest that intelligence is not important for initial attraction, which raises doubts concerning the sexual selection theory of intelligence.     

Investigating Neural Efficiency in the Visuo-Spatial Domain: An fmri Study

The neural efficiency hypothesis postulates an inverse relationship between intelligence and brain activation. Previous research suggests that gender and task modality represent two important moderators of the neural efficiency phenomenon. Since most of the existing studies on neural efficiency have used ERD in the EEG as a measure of brain activation, the central aim of this study was a more detailed analysis of this phenomenon by means of functional MRI. A sample of 20 males and 20 females, who had been screened for their visuo-spatial intelligence, was confronted with a mental rotation task employing an event-related approach. Results suggest that less intelligent individuals show a stronger deactivation of parts of the default mode network, as compared to more intelligent people. Furthermore, we found evidence of an interaction between task difficulty, intelligence and gender, indicating that more intelligent females show an increase in brain activation with an increase in task difficulty. These findings may contribute to a better understanding of the neural efficiency hypothesis, and possibly also of gender differences in the visuo-spatial domain.     

Homosexual behaviour and female-male mounting in mammals—a first survey

Information from the literature is given on the presence or absence of homosexual behaviour and female-male mounting in 125 species of mammals, both captive and wild. Such behaviour occurs in the male and often female young of many species soon after their birth. It is more common in young, often in play, than in adults. Adult homosexual behaviour is widespread in male and female mammals (recorded in 63 and 71 species respectively), but common in few species. In males it is most likely to be correlated with dominance and thus to occur in species with hierarchies such as terrestrial monkeys and members of the sheep and goat tribe. In females it is often correlated with sexual condition; a female in heat most often mounted another female, and one in heat was next most likely to be mounted by another female. Anoestral females rarely mounted other anoestral females. Females of 43 species mounted males, which often excited them sexually. Captive mammals tended to mount animals of the same sex more often than did wild ones when comparative data were available. Domestic animals also mounted more man did wild ones, with several exceptions. Some phylogenetic groups of animals displayed similar degrees of homosexual mounting, but there was often considerable variation between closely related species. Nor could homosexual mounting be always correlated with the social structure of a group. The four reasons for, or contexts of, homosexual and female-male mountings were social play (in 34 species), aggression (19 species), sexual excitement (36 species), and physical contact—non-play (30 species). This last category included a state of tension, getting attention, greeting, grooming, caressing, reassurance and appeasement. There was some overlap between categories. Homosexual pair-bonds occur in captive mammals and have been observed throughout the year in non-captive female Japanese monkeys.     

Common psychiatric problems in homosexual men and women consulting family physicians.

This paper describes the commoner psychiatric difficulties of homosexual patients seen in a family practice. It is written primarily to aid general practitioners in deciding who should be referred to a psychiatrist. Recent developments in the study of homosexuality indicate that homosexual persons are no more likely than heterosexuals to suffer psychiatric problems. Practical suggestions are made for management and counseling, and some of the misconceptions about the gay community are dispelled.     

Neophobia and its effect on the macro-structure and micro-structure of feeding in wild brown rats (Rattus norvegicus)

The effect of neophobia (fear of novelty) on feeding behaviour was examined in two groups of captive wild rats fed ad libitum. Different individuals employed different feeding patterns in response to novelty despite the absence of social and ecological constraints. The prevalent feeding pattern was to delay eating from a novel bowl several nights after it was introduced and, in general, novel food was sampled towards the end of a night. Systematic relationships (prandial correlations) were revealed in the meal pattern data which were consistent with the prediction that post-prandial correlations (controlled regular feeding bouts) are more likely in predictable environments. A large proportion of the individuals exhibited no prandial relationships which correlated with high levels of neophobia supporting the hypothesis that highly neophobic individuals are less able to regulate their feeding in the presence of novelty.     

A Juvenile Hormone analogue enhances homosexual behaviour in female‐deprived males of the migratory locust

In laboratory colonies of crowded migratory locusts Locusta migratoria (L.), homosexual behaviour (i.e. males mounting other males) is commonly observed. Female‐deprived males of Locusta migratoria migratorioides R. & F. mount each other in a characteristic mating position, often forming a group of several insects. When allatectomized males are placed together with intact, female‐deprived males, the former are usually mounted by the latter, demonstrating some degree of control involving the corpora allata over homosexual behaviour. This may be related to the positive effects of Juvenile Hormone (JH) or Juvenile Hormone analogues (JHAs) in enhancing male sexual behaviour, as is shown in some other insects. In the present study, a potent JHA (i.e. pyriproxyfen) is injected into a group of young, crowded L. m. migratorioides males, and an equivalent group of control males is maintained in a separate cage. Both groups are deprived of females. Three times a week, during 2‐h observation periods, JHA‐injected and control males are placed together in the absence of females, and homosexual mountings, per group and per individual, are recorded every 10 min. Observations are performed for 10 weeks. Analysis of these data, including the time spent in mounting behaviour, the percentage of individuals within a group involved in the behaviour during the observation periods and the identity of both partners, reveals that the JHA‐treated males show a more intense homosexual mating behaviour than control males in all quantified parameters. This is the first report of the enhancement of homosexual behaviour by an endocrine factor in insects.