The strength of associations among sexual strategy traits: Variations as a function of life history speed Heitor B.F. Fernandes, Michael A. Woodley of Menie, Claudio S. Hutz, Daniel J. Kruger, Aurelio José Figueredo Personality and Individual Differences (Aug 2016)
We hypothesize that sexual strategies are more diverse in slow life histories.
Two general population samples and one student sample are used from two countries.
Two factors are identified, related to sexual restriction and negative emotionality.
The weaker the factor loadings, the slower the life history, supporting hypothesis.
Sex and sample differences based on sample type and country are discussed.
Individuals exhibit differences in their life history strategies along a continuum that ranges from fast (involving investments in immediate rewards) to slow (involving long-term relationships and investments). Components of life history have been demonstrated to be more strongly correlated in individuals with faster life histories, a phenomenon termed Strategic Differentiation–Integration Effort (SD–IE). Sexual strategies are an intrinsic component of life history, yet have not been examined for SD–IE effects. We tested SD–IE in one student and two general population samples from two countries, among sexual strategy traits and correlates (sociosexual orientation, attachment avoidance, attachment anxiety, three groups of postcoital emotions, mate value, and life history speed). Two latent factors were found to explain the overall associations among these variables. The associations between the two factors and among their respective manifest indicators within factor were stronger in individuals with less restricted sexual strategies and more negative emotionality in sexual relationships, traits which are indicative of overall faster life history, supporting SD–IE hypotheses. Sex differences were identified and accounted for by life history speed differences between men and women. Unifactorial and multifactorial views of human sexual strategies can be argued to be equally supported by data, depending on individual life history speed.
Genetic distances are an indicator of evolutionary history of populations.
Genetic distances and IQ differences are positively correlated (r = .37).
Controlled for further factors there is a robust effect on IQ-differences (β = .22 to .40).
The robust effect of latitudinal differences supports an evolutionary explanation.
The study analyzes whether genetic differences (“genetic distances”) help to explain cross-national IQ differences being controlled for environmental factors. Genetic distances are an indicator of evolutionary history and of difference or similarity between populations. Controlled for environmental determinants the relationship between genetic distances and intelligence differences can be interpreted as an effect of genetic factors. Genetic distances were calculated in Y-chromosomal haplogroup frequencies betweenN = 101 national populations based on k = 27 genetic studies. Correlations and path-analyses with differences in geographical coordinates and the Human Development Index (HDI) as background and control factors revealed a positive impact of genetic distances on cross-national IQ-differences (r = .37, β = .22 to .40). The strongest impact was found for HDI (r = .67, β = .58). Longitudinal differences have no positive effect (r = −.09, β = −.13 to −.26), latitudinal differences have a positive one (r = .37, β = .07 to .21). The positive relationship to latitudinal differences underpins an evolutionary explanation. Chances and limits of this approach (e.g. no intelligence coding genes detected) understanding national differences in cognitive ability and the role of environmental factors are discussed.
Gijsbert Stoet , Drew H. Bailey , Alex M. Moore , David C. Geary (2016)
Despite international advancements in gender equality across a variety of societal domains, the underrepresentation of girls and women in Science, Technology, Engineering, and Mathematics (STEM) related fields persists. In this study, we explored the possibility that the sex difference in mathematics anxiety contributes to this disparity. More specifically, we tested a number of predictions from the prominent gender stratification model, which is the leading psychological theory of cross-national patterns of sex differences in mathematics anxiety and performance. To this end, we analyzed data from 761,655 15-year old students across 68 nations who participated in the Programme for International Student Assessment (PISA). Most importantly and contra predictions, we showed that economically developed and more gender equal countries have a lower overall level of mathematics anxiety, and yet a larger national sex difference in mathematics anxiety relative to less developed countries. Further, although relatively more mothers work in STEM fields in more developed countries, these parents valued, on average, mathematical competence more in their sons than their daughters. The proportion of mothers working in STEM was unrelated to sex differences in mathematics anxiety or performance. We propose that the gender stratification model fails to account for these national patterns and that an alternative model is needed. In the discussion, we suggest how an interaction between socio-cultural values and sex-specific psychological traits can better explain these patterns. We also discuss implications for policies aiming to increase girls’ STEM participation.
"I have suggested ... that the concept of free will has essentially nothing to do with the philosophical problem of physical causation, with which it is usually associated, but instead represents the freedom and ability to make decisions in our own individual interests as we see fit - to choose on our own among the alternative scenarios we are able by consciousness and foresight to see before us."
"Es gibt Menschen, für die ansonsten sehr selten geäußerte Meinungen einen größeren Anreiz besitzen als die Allerweltsmeinungen; andere Personen hingegen fühlen sich im Bewusstsein, eine von vielen geteilte Anschauung zu vertreten wohler und geborgener. Wie es jeweils darum bestellt ist, muss nicht immer von dauernden Eigenheiten eines Wesens abhängen.
Die Erfahrung lehrt, dass wir im Augenblick des Trotzes mehr den Minoritätsansichten, in Zeiten banger Stimmung mehr denen der Majorität zuneigen."
Face and Emotion Expression Processing and the Serotonin Transporter Polymorphism 5-HTTLPR/rs22531 Andrea Hildebrandt, Astrid Kiy, Martin Reuter, Werner Sommer and Oliver Wilhelm (2016)
Face cognition, including face identity and facial expression processing, is a crucial component of socio-emotional abilities, characterizing humans as highest developed social beings. However, for these trait domains molecular genetic studies investigating gene-behavior associations based on well-founded phenotype definitions are still rare. We examined the relationship between 5-HTTLPR/rs25531 polymorphisms – related to serotonin-reuptake – and the ability to perceive and recognize faces and emotional expressions in human faces. For this aim we conducted structural equation modeling on data from 230 young adults, obtained by using a comprehensive, multivariate task battery with maximal effort tasks. By additionally modeling fluid intelligence and immediate and delayed memory factors, we aimed to address the discriminant relationships of the 5-HTTLPR/rs25531 polymorphisms with socio-emotional abilities. We found a robust association between the 5-HTTLPR/rs25531 polymorphism and facial emotion perception. Carriers of two long (L) alleles outperformed carriers of one or two S alleles. Weaker associations were present for face identity perception and memory for emotional facial expressions. There was no association between the 5-HTTLPR/rs25531 polymorphism and non-social abilities, demonstrating discriminant validity of the relationships. We discuss the implications and possible neural mechanisms underlying these novel findings.
The Child Quality-Quantity Tradeoff, England, 1780-1880: A Fundamental Component of the Economic Theory of Growth is Missing
G Clark & N Cummins (April 2016)
In recent theorizing, modern economic growth was created by substituting child quality for quantity. However evidence for this tradeoff is minimal. In England the Industrial Revolution occurred in a period 1780-1879 of substantial human capital investment, but no fertility control, huge random variation in family sizes, and uncorrelated family size and parent quality. Yet family size variation had little effect on educational attainment, occupational status, or longevity, for both prosperous and poor families. More children reduced inherited wealth, but even that effect largely disappeared by the next generation. There is no quality-quantity tradeoff. Growth theory must proceed in other directions.
"Consciousness, foresight, self-awareness, conscience, and related aspects of the human psyche have evolved as a set of >overrides< of more widespread (and not necessarily solely human), generalized indicators of immediate costs and benefits. The most prominent and perhaps most general of such indicators of immediate costs and benefits are pain and pleasure. ..."
"Alexander et al. (1979; see also Alexander, 1975) have argued that socially or legally imposed monogamy is a way of leveling the reproductive opportunities of men, thereby reducing their competitiveness and increasing their likelihood of cooperativeness. The imposition of monogamy by custom or law has the interesting effect of reducing both male-male and male-female conflicts to a minimum, especially when clans are discouraged (as in nation states: see Alexander, 1979, pp 256-259), and when married couples do not have differential access to their respective relatives (e.g., when they are "neolocal" or reside in a new locality rather than becoming a part of one or the other extended family of relatives). Moreover, the combination of socially or legally imposed monogamy, neolocality, and close association of the married couple in work not only leads to minimizing of philandering and conflict of interest between husband and wife, but also characterizes the largest (and perhaps the most unified - or durable - of all large) human societies. ..."
"the most extremely ultrasocial systems of humans and other species are apparently all based on reproductive opportunity leveling."
The Biology of Moral Systems
Richard D. Alexander (1987)
"... Human mentality has several components, but consciousness is probably central. The concept of consciousness is related to other ideas like foresight, planning, awareness, self-awareness, fantasizing, and dreaming. All of these are part of anyone's description of human mentality. Among other things consciousness implies the ability to think about times and places and events separated from our immediate personal circumstances. It implies the ability to use information from the social past to anticipate and alter the social future, to build scenarios-to plan, to think ahead, and to anticipate different possible outcomes and retain the potential to act in several alternative ways, depending on circumstances that can only be imperfectly represented at the time the plans or scenarios are being made.
Language is tied closely to consciousness· as scenario-building, because it alone enables us to communicate with others about events "displaced" in space or time or both (Hockett, 1960) - a requisite characteristic of social (or other) scenarios. We can use signs or symbols to designate places, events, objects, and individuals, and then, through the use of tenses, talk to others about events, objects, or individuals in different times and places. In no other way can detailed information about mental scenarios, which necessarily involve different times and places, be transferred between individuals (see also Alexander, 1989b; Gibbard, 1990).
What circumstances should we expect to be most challenging, with respect to accurate and complete building of scenarios via consciousness? Surely, the answer is: those involving other organisms doing exactly the same thing in preparation for their competitive and cooperative interactions with us. In other words, nothing would select more potently for increased social intelligence-for better ability to look ahead and survey the alternatives accurately-than a within-species co-evolutionary race in which success depended on effectiveness in social competition. In effect, consciousness is a way of seeing ourselves as others see us so that we may cause competitive others to see us as we wish them to, rather than as they might like to (that is, with our "defenses" down).
I think that this view places cognition, as a part of problem-solving ability, in a clearer light as well, because it implies that the problems that have driven the evolution of cognitive abilities have been social problems. I have argued that other aspects of human mentality such as the expression of the emotions and personality traits are also parts of our supply of tools for social cooperation and competition (Alexander, 1989b). Psychologists and anthropologists have already suggested independently of the theories discussed here that mathematical ability is a special case of linguistic ability (Lenneberg, 1971), and that linguistic ability is likely explainable as serving a social function (Burling, 1986).
Scenario-building, including dreaming and daydreaming as well as serious or purposeful planning, has seemed to many a kind of social-intellectual play. The most widely accepted theory of play is that it represents practice for the future, which occurs under circumstances that make it inexpensive compared to real-life, full-cost episodes of social competition (Fagen, 1981; Humphrey, 1983). Such 'practice can take many forms. It can merely improve physical, social, or intellectual skills. It may involve producing and trying out alternative scenarios. It may also involve acquiring status, or learning how to deal with dominance rankings that may be difficult to change as the playing individuals grow and develop and begin to compete in earnest for the actual resources of reproductive success, such as mates, jobs, and status (Alexander, 1989b). The term "thought experiments," as used frequently by scientists, suggests the centrality of scenario-building. It refers to an initial, internal process of testing and rejecting possibilities, and in that sense I regard it as responsible for the generation of virtually every reasonable hypothesis. To the extent that useful ideas represent a limiting factor in the advance of knowledge, this process may be central in even the most conservative and rigorous aspects of science. Einstein completed the general theory of relativity in his brain and tested it there so thoroughly that he was confident that "The result could not be otherwise than correct. I was only concerned with putting the answer into a lucid form. I did not for one second doubt that it would agree with observation" (Clark, 1971, p. 259).
Every human continually builds hypotheses and initiates their testing within his own mind, whether he is dealing with high-level scientific questions or everyday problems like how to start a car or whether or not to cross the street in some particular place or time. Such thought-experiments work because every human already has some relevant data in his head when he generates an hypothesis. The skill with which the process of internal testing is undertaken, and the data that already exist in the theorist's head against which he can test his idea, are what determines whether the hypothesis, when it is finally communicated to others, will be reasonable and useful, or will immediately be seen as false or unacceptable because of someone else's thought experiments. Reviewing possibilities and probabilities, and mentally playing out step-by-step either physical or mental challenges that lie ahead, are widely believed to be sometimes more important than more direct forms of practice. Even the actual experimental testing of an hypothesis, after all, is itself nothing more than a mental scenario brought out into the external world."
"mittlerweile sind wir terminologisch dahin gekommen, dass wir die postindustriellen oder postmateriellen Werte als das Wesentliche ansehen. Die industriellen Werte waren Ordnung, Sparsamkeit, Fleiß und so weiter, die postindustriellen sind Selbstverwirklichung, Kommunikation und so weiter. Ich glaube nicht, dass mit diesen Werten großer Staat zu machen ist, aber sie sind natürlich sehr beliebt, weil sie im Grunde Leerformeln sind, in die jeder hineinlegen kann, was ihm gerade passt. Das wird irgendwann zu großen Schwierigkeiten führen, weil dadurch Unsicherheit verbreitet wird. Wenn ich weiß, was falsch ist, kann ich mich einigermaßen danach richten und das vermeiden. Wenn aber alles richtig ist, finde ich mich nicht mehr zurecht."
"Seltsam schnell, d.h. innerhalb weniger Jahre hat die sog. Universitätsreform dazu geführt, dass für eine nicht geringe Anzahl von Hochschullehrern ihr Beruf zu einem >job< geworden ist, um den man sich zu bewerben hat und in dem ein Pensum abzuleisten gilt (z.B. >Forschung< im Ausmaß von >14 Stunden wöchentlich übers Jahr<); der aber für die Selbstverwirklichung - die eigentliche >professio< - nicht mehr taugt. ...
Diese Entwicklung dürfte sich kaum aufhalten oder rückgängig machen lassen. Man sollte sich nur darüber im klaren sein, dass die Hochschulen auf diese Weise zu recht öden Lehranstalten werden müssen ..."
Detecting affiliation in colaughter across 24 societies
Gregory A. Bryant et al. (March 2016)
Human cooperation requires reliable communication about social intentions and alliances. Although laughter is a phylogenetically conserved vocalization linked to affiliative behavior in nonhuman primates, its functions in modern humans are not well understood. We show that judges all around the world, hearing only brief instances of colaughter produced by pairs of American English speakers in real conversations, are able to reliably identify friends and strangers. Participants’ judgments of friendship status were linked to acoustic features of laughs known to be associated with spontaneous production and high arousal. These findings strongly suggest that colaughter is universally perceivable as a reliable indicator of relationship quality, and contribute to our understanding of how nonverbal communicative behavior might have facilitated the evolution of cooperation.
Laughter is a nonverbal vocal expression that often communicates positive affect and cooperative intent in humans. Temporally coincident laughter occurring within groups is a potentially rich cue of affiliation to overhearers. We examined listeners’ judgments of affiliation based on brief, decontextualized instances of colaughter between either established friends or recently acquainted strangers. In a sample of 966 participants from 24 societies, people reliably distinguished friends from strangers with an accuracy of 53–67%. Acoustic analyses of the individual laughter segments revealed that, across cultures, listeners’ judgments were consistently predicted by voicing dynamics, suggesting perceptual sensitivity to emotionally triggered spontaneous production. Colaughter affords rapid and accurate appraisals of affiliation that transcend cultural and linguistic boundaries, and may constitute a universal means of signaling cooperative relationships.
Going All In: Unfavorable Sex Ratios Attenuate Choice Diversification
Joshua M. Ackerman, Jon K. Maner, and Stephanie M. Carpenter Psychol Sci (April 2016)
When faced with risky decisions, people typically choose to diversify their choices by allocating resources across a variety of options and thus avoid putting "all their eggs in one basket." The current research revealed that this tendency is reversed when people face an important cue to mating-related risk: skew in the operational sex ratio, or the ratio of men to women in the local environment. Counter to the typical strategy of choice diversification, findings from four studies demonstrated that the presence of romantically unfavorable sex ratios (those featuring more same-sex than opposite-sex individuals) led heterosexual people to diversify financial resources less and instead concentrate investment in high-risk/high-return options when making lottery, stock-pool, retirement-account, and research-funding decisions. These studies shed light on a key process by which people manage risks to mating success implied by unfavorable interpersonal environments. These choice patterns have important implications for mating behavior as well as other everyday forms of decision making.
What Predicts Romantic Relationship Satisfaction and Mate Retention Intensity: Mate Preference Fulfillment or Mate Value Discrepancies?
Daniel Conroy-Beam, Cari D. Goetz, David M. Buss Evolution and Human Behavior (April 2016)
We test a novel evolutionary hypothesis predicting that mate value discrepancies, but not mate preference fulfillment, will regulate relationship satisfaction. Across Study 1 (n = 259) and Study 2 (n = 300), we employed new Euclidean measures able to capture preference fulfillment and compute estimates of mate value discrepancies. Relationship satisfaction was not related to how well mates fulfilled their partner’s preferences. Mate value discrepancies, in contrast, interacted to predict relationship satisfaction: relationship satisfaction declined for participants whose mates were less desirable than their alternatives, but only for participants who were higher in mate value than their mates. Additionally, these satisfaction differences mediated a relationship between mate value discrepancies and mate retention behavior. This mediation pathway is unique to satisfaction; the same pathway was not observed through trust, a functionally distinct relationship affective state. Study 3 (n = 301) addressed a methodological limitation of Studies 1 and 2. We replicated the mate value discrepancy interaction to predict relationship satisfaction, but found an effect of ideal preference fulfillment on relationship satisfaction. These results provide the first evidence that mate preferences have important, functionally specific effects on within-relationship processes through contributing to two independent discrepancy variables: partner-self and partner-potential mate value discrepancies. They also contravene the hypothesis that mate preference fulfillment is the key to relationship satisfaction.
"Reviewing possibilities and probabilities, and mentally playing out step-by-step either physical or mental challenges that lie ahead, are widely believed to be sometimes more important than more direct forms of practice."
>There have been few efforts to characterize the human psyche in terms
useful to those who would understand and reconstruct its functional aspects
from a modern evolutionary viewpoint (but see Premack and Woodruff
1978; Griffin 1978; Savage-Rumbaugh et al. 1978, and the accompanying
commentaries). I think the key argument (Humphrey 1976, 1978, 1983;
Alexander 1979, 1987) is that consciousness represents a system of (1)
building scenarios or constructing possible (imagined) alternatives; (2) testing
and adjusting them according to different projected circumstances; and
(3) eventually using them according to whatever circumstances actually
arise. Earlier, I referred to such abilities as the capacity to over-ride
immediate rewards and punishments in the interests of securing greater
rewards visualized in the future (Alexander 1987). In this view, consciousness,
cognition, and related attributes - which probably represent the core
of the problem in understanding the human psyche - have their value in
social matters, and the operation of consciousness can be compared to the
planning that takes place in a game in which the moves of the other players
cannot be known with certainty ahead of time. In other words, by this
hypothesis, the function of consciousness is to provide a uniquely effective
foresight, originally functional (sensu Williams 1966) in social matters, but
obviously useful, eventually, in all manner of life circumstances. I will
argue (below) that the emotions, linguistic ability, and personality traits
are primarily communicative devices, hence, also social in their function.
The above view of the psyche is compatible with that of cognitive
psychologists, such as Neisser (1976). Cognitive psychologists, however,
concentrate more on mechanisms than on function, and so the idea that
the use of cognition might have evolved explicitly in the context of social
competition seems not to have emerged in their arguments. Nevertheless,
Neisser's insistence on use of the concept of 'schemata' as plans, representing
what is here called scenario-building, is a close parallel to Humphrey's
arguments and my own. It is clear that a merging of ideas is likely to be
easy, and profitable.<
>Consciousness is a system by which we are in some sense aware of ourselves and our relationship to others and the rest of the world. For this reason I regard it as most likely evolved in the context of success in social matters. My own introspection, and my observation of others, suggest to me that how others see us is absolutely crucial to social success, however success is defined. It appears to me that consciousness is largely a system for testing the question of how others see us and adjusting our image in our own self-interest - that is a vehicle for, as Robert Burns put it, seeing ourselves as others see us.
A central aspect of consciousness is the ability to look ahead, the capability that we call "foresight". It is the ability to plan, and in social terms the ability to outline a scenario of what is likely going to happen, or what might happen, in social interactions that have not yet taken place. The significance of that ability is obvious. It is a system whereby we improve our chances of doing those things that will represent our own best interests. We consider what will happen if - if we do this or if we do that; and we try to judge what others with whom we expect to interact will do, under each of several circumstances, and to figure out how to get them to behave as we would like them to. We draw up alternatives and consider them, one by one. It is especially significant that we do this so prominently in the connection with social interactions, for no other life situations are quite so uncertain, or so important to plan out ahead of time. The reason is that those with whom we interact are also capable of scenario-building, and so their behavior will be tuned to their own particular interests and their own efforts to anticipate our responses. No feature of the environment is quite so difficult to figure out as what to expect from other social beings with whom we must interact, each of whom is attempting with all the capabilities he can muster to adjust the outcomes of our interactions with him to his own advantage, rather than to ours, when our interests differ.
In the course of using our consciousness and foresight to build scenarios and plan our social interactions, we visualize alternatives and test them one by one. We see these different alternatives available to us if we choose to use them, and in some sense they are - or at least some of them are. I believe that it is our ability to visualize alternatives, particularly in connection with social interactions, that represents the basis of the concept free will. We see points of decision ahead of us because we have used all the information we can muster from the past and present to build future scenarios about our immediate futures, and I suggest that "free will" is our apparent ability to choose and act upon whichever of these decisions seem most useful or appropriate, and our insistence upon the idea that such choices are our own. ...<
>Consciousness can be defined as knowing what you are thinking about and being
able to tell others about it and act on it as a matter of self-understood choice among
envisioned alternatives in subsequent social or other situations. It implies the ability
to think about times, places, and events separated from your immediate circumstances
and the ability to use the understanding so gained to anticipate and alter the
future, build further scenarios, plan and think ahead, anticipate different possible
outcomes, and retain the potential to act in several alternative ways, depending on
circumstances that can be only imperfectly represented at the time the plans or
scenarios are being made. Language is a concomitant of consciousness, characterized
by features that make communication of useful information about mental
scenarios possible: signs, symbols, and displacement in time or space (Hockett
1960; Alexander 1979a, 1983; Pinker 1994, 1997).<
"One's willingness to take risks depends in large part upon the relative values that one places on success and failure. A person whose appetite for success exceeds his aversion to failure will be inclined toward action; a person whose aversion to failure exceeds his appetite for success will be inclined not to act."
"the reproductive consequences for anxious, depressed or generally neurotic men are predicted to be more severe than for equally or more strongly affected women. Results from associated studies are mixed but generally consistent with the prediction that anxiety and depression negatively influence men's reproductive prospects and either do not affect or more weakly affect those of women (Berg et al, 2014; Gruven et al, 2014; Jokela, Alvergne, Pollet, & Lummaa, 2011; Reis, Dörnte, & von der Lippe, 2011)."
"we know that lower-status men in modern contexts are more prone to physical aggression and physical risk taking than are higher status men (Argyle, 1994; Wilson & Daly, 1985); higher status men take financial and occupational, not physical risks."
"there are many working class people with high I.Q.s, and there are some middle class people with low I.Q.s. The overlap is greater in the lower social classes; it is easier to have a high I.Q. and lose out in the occupational stakes for reasons of bad luck, bad health, lack of persistence, or mental illness, than it is to get past the many hurdles, educational and otherwise, which bestrew the path to middle class success, with a low I.Q."
Hans J. Eysenck
"it is not nearly as difficult to find gifted children (IQs above 130) in the lower classes as it is to find mildly retarded children in the upper classes."
"Individualism implies what one might term a rational market economy in human relationships..."
"Marriage for Europeans was thus far more based on individual choice than on
cementing kinship relationships by, for example, marrying first cousins whatever their
traits (which is the pattern in much of the rest of the world). Again, as a result of
individualism, Western relationships, including marriage, are more market oriented
(predisposing to capitalism as an economic system): those with attractive traits,
including physical beauty (especially the case with women), do well on the marriage market. Besides physical traits, psychological attraction (especially love)—another
aspect of individual choice—has been valued far more in Western culture than the other
cultures of the world."
"You could say that in Japan anything you do is prescribed for maximum predictability. From cradle to grave, life is highly ritualized and you have a lot of ceremonies. For example, there is opening and closing ceremonies of every school year which are conducted almost exactly the same way everywhere in Japan. At weddings, funerals and other important social events, what people wear and how people should behave are prescribed in great detail in etiquette books. School teachers and public servants are reluctant to do things without precedence. In corporate Japan, a lot of time and effort is put into feasibility studies and all the risk factors must be worked out before any project can start. Managers ask for all the detailed facts and figures before taking any decision. This high need for Uncertainty Avoidance is one of the reasons why changes are so difficult to realize in Japan."
Ability tilt for whites and blacks: Support for differentiation and investment theories
Thomas R. Coyle (2016) Intelligence
Ability tilt refers to within-subject differences in math and verbal scores on aptitude tests.
Math tilt (math > verbal) and verbal tilt (verbal > math) were examined for whites and blacks.
Math tilt was higher for whites than blacks; verbal tilt was similar for both groups.
Tilt positively predicted similar abilities, and negatively predicted competing abilities.
Tilt effects were stronger for whites, supporting differentiation and investment theories.
This research is the first to examine race differences in ability tilt for whites and blacks, two groups that show an average difference in g (favoring whites) of about one standard deviation. Tilt was defined as within-subject differences in math and verbal scores on three aptitude tests (SAT, ACT, PSAT). These differences yielded math tilt (math > verbal) and verbal tilt (verbal > math), which were correlated with specific abilities (verbal and math) and college majors in STEM (science, technology, engineering, math) and the humanities. Math tilt was higher for whites than blacks, whereas verbal tilt was similar for both groups. In addition, tilt correlated positively with similar majors and abilities (e.g., math tilt and math ability), and negatively with competing majors and abilities (e.g., math tilt and verbal ability). Tilt effects were generally stronger for whites, and were unrelated to g. The results support differentiation theories, which predict higher levels of tilt for higher ability subjects, and investment theories, which predict negative tilt effects for competing abilities (e.g., math tilt and verbal ability).
The purpose of this study is to examine variance in the practice and acceptance of cousin marriage in select areas of the world. This study uses Murdock’s Standard Cross Cultural Sample (SCCS). The SCCS includes 186 societies ranging from contemporary hunter and gatherers to early historic states to contemporary industrial people. It is hypothesized that cousin marriages are more likely to occur in small, isolated communities, and in communities that experience high rates of pathogen prevalence. That is, the variance in the practice of cousin marriage may reflect functional responses to various local ecological and environmental pressures. The results demonstrate that geographic isolation and pathogen prevalence are both independent and significant positive predictors of whether or not a society practices cousin marriage. These findings suggest that consanguineous marriage may be an adaptive solution to the problem of mate selection, depending on the environment in which one lives. Consequently, the biological advantages may lead to and/or become an individual preference, which is then reinforced by the local culture. We contend that although social and cultural explanations are of obvious importance, they can only provide partial explanations, and much can be gained from incorporating an evolutionary perspective.
Although girls and women in many societies avidly participate in sports, they have been traditionally underrepresented compared with boys and men. In this review, we address the apparent sex differences in sports interest and motivation from an evolutionary perspective. First, we demonstrate that females’ underrepresentation generally reflects lesser interest, not merely fewer opportunities for engagement. Moreover, there is mounting evidence that male and female athletes generally differ in their motivation, specifically their competitiveness and risk taking. Second, we examine the functional explanations for sports. We argue that the courtship display hypothesis applies mainly to females; the spectator lek hypothesis applies chiefly to males; and that 2 other hypotheses—the allying with coalitions hypothesis and the development of skills hypothesis—are important for both females and males. Third, we explore the proximate causes for the sex differences in sports interest and motivation. We show that although there is compelling evidence that prenatal hormones contribute, the evidence that socialization plays a role remains equivocal. We conclude by discussing key findings and identifying areas for further research.
This paper begins with a list of commonly recognized forms of play and a discussion of definitions
of play. This is followed by an overview of the ontogeny, phylogeny, mechanisms, and possible
functions of human play. Next the question of whether or not play should be regarded as a
separate emotion from interest is addressed. Play resembles the emotion of interest (or curiosity) in
its affects and cognitive elicitors. Play differs from interest in exhibiting somewhat distinctive
behavioral, visceral, and expressive emotional properties. This evidence, together with phylogenetic
information, suggests that interest, exploration, and play constitute the same basic emotion, with
exploration being an evolutionary offshoot of interest and play an offshoot of exploration.