In both biology and the human sciences, social groups are sometimes treated as adaptive units whose organization cannot be reduced to individual interactions. This group-level view is opposed by a more individualistic one that treats social organization as a byproduct of self-interest. According to biologists, group-level adaptations can evolve only by a process of natural selection at the group level. Most biologists rejected group selection as an important evolutionary force during the 1960s and 1970s but a positive literature began to grow during the 1970s and is rapidly expanding today. We review this recent literature and its implications for human evolutionary biology. We show that the rejection of group selection was based on a misplaced emphasis on genes as “replicators” which is in fact irrelevant to the question of whether groups can be like individuals in their functional organization. The fundamental question is whether social groups and other higher-level entities can be “vehicles” of selection. When this elementary fact is recognized, group selection emerges as an important force in nature and what seem to be competing theories, such as kin selection and reciprocity, reappear as special cases of group selection. The result is a unified theory of natural selection that operates on a nested hierarchy of units.
 The vehicle-based theory makes it clear that group selection is an important force to consider in human evolution. Humans can facultatively span the full range from self-interested individuals to “organs” of group-level “organisms.” Human behavior not only reflects the balance between levels of selection but it can also alter the balance through the construction of social structures that have the effect of reducing fitness differences within groups, concentrating natural selection (and functional organization) at the group level. These social structures and the cognitive abilities that produce them allow group selection to be important even among large groups of unrelated individuals.

Reintroducing group selection to the human behavioral sciences

Gru nd legung zur Metaphysik der Sitten

A Study of Concepts

Knowledge in Flux

The fundamental postulate of sociobiology is that individuals exploit favorable environments to increase their genetic representation in the next generation. The data on fertility differentials among contemporary humans are not cotvietent with this postulate. Given the importance of Homo sapiens as an animal species in the natural world today, these data constitute particularly challenging and interesting problem for both human sociobiology and sociobiology as a whole.The first part of this paper reviews the evidence showing an inverse relationship between reproductive fitness and “endowment” (i.e. wealth, success, and measured aptitudes) in contemporary, urbanized societies. It is shown that a positive relationship is observed only for those cohorts who bore their children during a unique period of rising fertility, 1935–1960, and that these cohorts are most often cited by sociobiologists as supporting the central postulate of sociobiology. Cohorts preceding and following these show the characteristic inverse relationship between endowment and fertility. The second section reviews the existing so-ciobiological models of this inverse relationship, namely, those of Barkow, Burley, and Irons, as well as more informal responses among sociobiologists to the persistent violation of sociobiology's central postulate, such as those of Alexander and Dawkins. The third section asks whether the goals of sociobiology, given the violation of its fundamental postulate by contemporary human societies, might not be better thought of as applied rather than descriptive, with respect to these societies. A proper answer to this question begins with the measurement of the pace and direction of natural selection within modern human populations, as compared to other sources of change. The vast preponderance of the shifts in human trait distributions, including the IQ distribution, appears to be due to environmental rather than genetic change. However, there remains the question of just how elastic these distributions are in the absence of reinforcing genetic change.

Social versus reproductive success: The central theoretical problem of human sociobiology

This study takes a careful inferentialist look at Graham Priest’s Logic of Paradox (LP). I conclude that it is sorely in need of a proof-system that could furnish formal proofs that would regiment faithfully the “naive logical” reasoning that could be undertaken by a rational thinker within LP (if indeed such reasoning could ever take place).

GP’s LP

need a stronger, a definitive criterion. In natural science (and so too I believe in good psychological, medical and social science) this criterion is met by demanding a demonstration of or plausible hypothesis concerning a gener ative influence from items of kind A to items of kind B, usually through some generative mechanism. In fundamental science causation occurs through some basic system of influences such as electro-magnetic fields. A simple example should make this dual criterion demand clear. To establish that smoking causes lung cancer one must not only establish a good statistical relation, that is satisfy the prima facie criterion, but also establish how smoking generates or produces cancers, that is satisfy the definitive criterion. The first criterion demands surveys and statistics and is based on the extensive design, the second demands biochemistry and physiology and is based on the intensive design, that is on the deep and detailed investigation of single cases treated as typical of the class of cases to be studied. Before I turn to examine his case against Brown et al with a more powerful conception of causality to hand than that Bebbington wields in his discussion, I need to draw attention to a terminological inexactitude that Dr Bebbington is not alone in employing. He speaks in several places of causal â€ ̃¿ models'. Now a model is a simulacrum of something; sometimes this takes the form of an idealization of its subject, some times it is an analogue. I am unable to identify either of these senses of â€ ̃¿ model' with Bebbing ton's usage. He seems to me to mean â€ ̃¿ hypo thesis' when he speaks of â€ ̃¿ model', for those things he calls causal models are various hypo theses as to what is causally related to what. I shall proceed then as if he is talking about hypotheses and not about models, since his remarks are meaningless iftaken literally. All of Dr Bebbington's arguments concern variations of the prima fade criterion, that is whether one should admit other concornit ances into the story. So far as I can see his reasoning is impeccable. So we are driven to consider a variety of additional putative causal factors. And the one to pay attention to is an alleged â€ ̃¿ vulnerability' factor. Bebbington points out, correctly I think, that the method of testing the hypothesis (not the model!) asso ciated with this factor is defective. But then he and I must part companyâ€”for, instead of now condemning Brown et al for continuing to occupy themselves only with the prima fade criterion and the extensive design, he plunges into a further exercise in statistical analysis. Ironically he reaches the same conclusion that could be reached directly by an attempt to design an intensive test of the vulnerability hypothesisâ€”'it remains unclear' he says, â€ ̃¿ how the factors (of the vulnerability components) could operate as provoking agents'. But it remains unclear only if we shy away from the intensive step. The next stage in a truly scientific programme of research would be to take two or three cases as types, each representative of the possibility that a vulnerability factor could be a provoking agent, and get down to brass tacks to see how in each particular case it worked. Then classes of cases could be reconstructed by defining each as the set of cases sufficiently like the case taken as the centre piece of an intensive design.

Causes and logic in epidemiological psychiatry. 2. Causal models and logical inference.

We explicate the different ways that a first-order sentence can be true (resp., false) in a model M, as formal objects, called (M-relative) truth-makers (resp., falsity-makers). M-relative truth-makers and falsity-makers are co-inductively definable, by appeal to the “atomic facts” in M, and to certain rules of verification and of falsification, collectively called rules of evaluation. Each logical operator has a rule of verification, much like an introduction rule; and a rule of falsification, much like an elimination rule. Applications of the rules (∀) and (∃) involve infinite furcation when the domain of M is infinite. But even in the infinite case, truth-makers and falsity-makers are tree-like objects whose branches are at most finitely long. A sentence φ is true (resp., false) in a model M (in the sense of Tarski) if and only if there existsπ such that π is an M-relative truth-maker (resp., falsity-maker) for φ. With “ways of being true” explicated as these logical truthmakers, one can re-conceive logical consequence between given premises and a conclusion. It obtains just in case there is a suitable method for transforming M-relative truthmakers for the premises into an M-relative truthmaker for the conclusion, whatever the model M may be.

A Logical Theory of Truth-Makers and Falsity-Makers

How is meaning possible

Christopher Peacocke, in «A study of concepts», motivates his account of possession conditions for concepts by means of an alleged parallel with the conditions under wich numbers are abstracted to give the numerosity of a predicate. There are, however, logical mistakes in Peacock's treatment of numbers, which undermine his intended analogy. Nevertheless Peacocke's account of possession conditions for concepts is not rendered inadequate simply by virtue of being deprived of the intended analogy and the motivation it was supposed to afford. His account of concepts deserves still to be considered on its own merits, even if it is more idiosyncratic for being isolated from the paradigm case of numerical abstraction. Peacocke's own account of concepts as abstract objects turns out, though, not to have the logical form of the kind he requires. Then we re-formulate it so to achieve complete generality. This exercise helps to clarifiy the central theses in Peacocke's acount of concepts. It invites the conclusion that his account of content-determination is rather platitudinous and unoriginal - except for a claim of doxastic sufficiency for content-determination, which emerges at the end of the discussion.

Neil Tennant

Papers

GP’s LP

Causes and logic in epidemiological psychiatry. 2. Causal models and logical inference.

A Logical Theory of Truth-Makers and Falsity-Makers

How is meaning possible

The Emperor’s New Concepts