Post-adoption incest and phenotypic matching: experience, personal meanings and biosocial implications

A teleofunctional account of evolutionary mismatch

When the environment in which an organism lives deviates in some essential way from that to which it is adapted, this is described as "evolutionary mismatch," or "evolutionary novelty." The notion of mismatch plays an important role, explicitly or implicitly, in evolution-informed cognitive psychology, clinical psychology, and medicine. The evolutionary novelty of our contemporary environment is thought to have significant implications for our health and well-being. However, scientists have generally been working without a clear definition of mismatch. This paper defines mismatch as deviations in the environment that render biological traits unable, or impaired in their ability, to produce their selected effects (i.e., to perform their proper functions in Neander's sense). The machinery developed by Millikan in connection with her account of proper function, and with her related teleosemantic account of representation, is used to identify four major types, and several subtypes, of evolutionary mismatch. While the taxonomy offered here does not in itself resolve any scientific debates, the hope is that it can be used to better formulate empirical hypotheses concerning the effects of mismatch. To illustrate, it is used to show that the controversial hypothesis that general intelligence evolved as an adaptation to handle evolutionary novelty can, contra some critics, be formulated in a conceptually coherent way.

Incest avoidance: oedipal and preoedipal, natural and cultural

Why do most people experience a subjective aversion to the idea of incestuous sexual relations? To help answer this question, recent strands of thinking in both cultural and evolutionary anthropology are considered together with psychoanalytic theories regarding incest avoidance. Coevolutionary theories that propose ways to think about genetic and cultural inheritance as partially independent of each other, evolutionary arguments about the reproductive advantages of incest avoidance, structuralist theory arguing for a kind of incest aversion unrelated to any possible Darwinian selective advantage, and other trends in biosocial research into the origins of the incest avoidance are considered. Finally, a synthesis is proposed that seeks to expand our understanding of the oedipal and preoedipal dynamics of the aversion as these are conceptualized in psychoanalytic theory.

Beyond Westermarck: Can Shared Mothering or Maternal Phenotype Matching Account for Incest Avoidance?

Westermarck's Hypothesis (WH) is widely accepted amongst evolutionary scientists as the best explanation of human incest avoidance. Although WH may account for incest avoidance between co-reared kin, it cannot explain other forms of incest avoidance, and therefore, cannot account for the differential incidence of sibling-sibling, mother-son, father-daughter and other forms of incest. WH also face problems adequately accounting for phenomena within its explanatory domain. Neither of the studies widely thought to corroborate WH (the Israeli kibbutz and Taiwanese simpua marriage studies) provides a genuine test of it, and the results of experimental thought to confirm WH are vitiated by methodological problems. The present paper considers two alternatives to WH: the shared mother hypothesis (SMH) and the maternal phenotype-matching hypothesis (MPMH). SMH states that human infants imprint on their mother, who then treat as kin those individuals towards whom their mother behaves in a kin-like or mate-like manner. MPMH states that humans unconsciously use the maternal phenotype as a visual template for estimating coefficients of relatedness, and that these estimate regulate altruistic and mating behavior. Both SMH and MPMH are able to account for the kibbutz and simpua marriage data, and entail additional epidemiological and experimental predictions. SMH and MPMH have greater explanatory power than WH, and MPMH has greater explanatory power than SMH.

Humour as Resistance: Deviance and Pathology from a Ludic Perspective

Humour, as one aspect of the ludic, has been argued to evolve with humankind as a higher order of social cognition. In a slum community known for its social dysfunctions and multiple psychopathologies, street humour is used to re-classify messages, situations and relationships, in a variety of contexts. How can we make sense of the discontinuity? This paper builds on work reported in a previous one (Cardeña 2003 ). Departing from information collected through participant observation, document analysis and clinical work carried with the community, the first paper documented the ways in which humour aids the assertion of a social identity. In the current paper, this point is developed further to scrutinize the role of 'pathology' under the light of a theory of humour, the ludic and meta-communication. The need to address the stature of socially patterned psychopathology as communicative act is emphasized. Deviant and aberrant behaviour, as ludic processes in the culture, embody a higher order of signification that is often overlooked by mental health agents. The failure at addressing this complexity halts the communication between the community's locals and the mental health agents, feeding back the kind of detrimental paradoxes that are at the core of the local's resistance.

Incestuous gene in consanguinophilia and incest: Toward a consilience theory of incest taboo

Westermarck's theory of incest taboo states that inhibition of sexual attraction between biologically close relatives is situational and develops during co-residence in early childhood. By contrast, the biological (genetic) basis of incest taboo is presumed from its universality in all human societies and animals and teleologically, from the need to prevent the detrimental effects of inbreeding. As incest taboo violation is infrequent, the frequency of the presumed gene in the population is believed to be near 100%. We present arguments which suggest that the incestuous gene may exist in all populations and could play an important role in evolution. When malaria emerged 10,000 years ago, human adaptation proceeded by the selection of protective genotypes. Among them, homozygotes for alpha-thalassemia, hemoglobin C, and Duffy antigen negative blood group, have better survival odds in malarious regions than heterozygotes and those with normal genotypes. Since consanguinity increases homozygosity, it increases the number of persons who are resistant to malaria. To pro-create, however, biologically close individuals must not feel sexual aversion that normally develops between those who spend their early childhood together (Westermarck effect). It is reasonable to assume, therefore, that mutation of the gene that discourages inbreeding may have appeared at an early time in evolution, and produced a weak Westermarck effect. This gene (we will call it anti-w) failed to inhibit mating between kins. Inbred offspring of anti-w carriers, would statistically, more likely carry both anti-w and homozygote genotypes which increase fitness in the presence of malaria. Today, alpha-thalassemia is the single most common monogenetic disorders in man with over 500 millions carriers concentrated in malarious regions of the world. The world's consanguineous population is some 500-800 millions and is also concentrated in malarious regions. Population migration has spread the gene outside areas of high malaria endemicity. However, endemicity of malaria provides a worldwide gradient of genotype frequencies which makes the incestuous gene hypothesis testable. We propose that the incestuous anti-w allele was co-selected with some of the genes protective against malaria because anti-w facilitates mating between genetically close individuals whose offspring better survive malaria.

Early separation and sibling incest. A test of the revised Westermarck theory

This was a follow-up study of earlier reported findings by the present investigators suggesting, albeit equivocally, that separation during early childhood inhibited later sexual acts of a potentially procreative nature between siblings but did not deter other sexual activity. The present study surveyed 170 subjects, mostly in the Toronto area, by telephone and mail. Respondents reporting potentially procreative, postchildhood sexual acts (attempted or completed genital intercourse) with siblings were compared with those reporting sexual relationships excluding procreative acts, and a third sample reporting no postchildhood sibling sexual behavior. Consonant with expectations from the earlier study, prolonged separation during early childhood was associated with procreative postchildhood sexual activity but not with other postchildhood sexual activity. Contrary to predictions, however, both sexual activity groups reported significantly more nudity and physical contact with siblings during childhood than subjects reporting no sexual activity. The findings are discussed in terms of a revised version of the Westermarck hypothesis, which is consistent with a domain-specific approach to evolved incest avoidance mechanisms.