Brain size has increased threefold during the course of human evolution, whilst body weight has approximately doubled. These increases in brain and body size suggest that reproductive rates must have slowed considerably during this period. During the same period, however, environmental heterogeneity has increased substantially. A central tenet of life-history theory states that in heterogeneous environments, organisms with fast life histories will be favoured. The human lineage, therefore, has proceeded in direct contradiction of this theory. This contribution attempts to resolve (...) this contradiction by recourse to Godfrey-Smith’s Environmental Complexity Thesis, which states that the function of cognition is to enable the organism to deal with environmental complexity. It is suggested that among slowly reproducing organisms the behavioural flexibility provided by advanced cognitive abilities is a fundamental component of adaptation to heterogeneous environments. In the human lineage this flexibility is manifest particularly in the increasing complexity of material culture. (shrink)

This paper offers an analysis of work on human development in evolutionary anthropology from a Thomist perspective. I show that both fields view care for others as fundamental to human nature and interpret cooperative breeding as expression of the virtue of charity. I begin with an analysis of different approaches to the relationship between evolutionary anthropology and moral theory. I argue that ethical naturalism is the approach best suited to interdisciplinary dialogue, since it holds that natural facts are useful for (...) moral theory but do not encompass it. This forms the basis for a Thomist analysis of some key features of human evolution including bipedalism, higher encephalisation and extended childhood. In each case I explain how these parts of our nature contributed to the evolution of modern humans, and how each is reliant upon communal care. Finally, I offer three observations on these facts from a Thomist perspective. Firstly, that a good human life necessarily involves caring for others and being cared for ourselves. Secondly, that this is exemplified in the virtue of charity, which is the ground of all virtue. Finally, that the need for such care shows that human flourishing cannot be attained without divine aid. (shrink)

Human beings, as we know and understand them today, are the result of a lengthy, two million year old process that has made them one of the most powerful and beautiful biological beings. The process of encephalisation in humans, combined with the development of areas of speech, brought about by a neurological reorganisation that may have taken place before the increase in brain size, has enabled humanity to generate a tremendous cognitive capacity that in turn has led to the (...) development of what we know of as culture. Culture influences biological development. No other species has achieved the like anywhere. For human survival, culture is a new dimension, a new habitat, which humanity has to adapt as it creates it. Culture is not written into the genome, but it can be transmitted and communicated thanks to speech. This enables knowledge to be shared and transmitted to other members of the group or society, to communicate ideas, concepts and abstractions. Knowledge enables a society to form a structure and make it more complex than a simple agglomeration of individuals while also creating an environment where raising children is viable since it can guarantee their survival, giving them the right treatment to enable them to reach adulthood. It has been said that ‘humanity is a spirit in time ’, hence the need to understand the essence of human natural history; the importance of paying it sufficient attention to ensure that what is attractive about its history does not become indigestible. (shrink)

An element of the contemporary dispute amongst evolution minded psychologists and social scientists hinges on the conception of mind as being adapted as opposed to adaptive. This dispute is not trivial. The possibility that human minds are both adapted and adaptive courtesy of selection pressures that were social in nature is of particular interest to a putative evolutionary social psychology. I suggest that the notion of an evolved psychological adaptation in social psychology can be retained only if it is accepted (...) that this adaptation is for social interaction and has no rigidly fixed function and cannot be described in terms of algorithmic decision rules or fixed inferential procedures. What is held to be the reason for encephalisation in the Homo lineage and some of best atested ideas in social psychology offers license for such an approach. (shrink)

What parameters determine brain size? This question is of particular interest for humans because our large brains confer outstanding cognitive abilities. The answer has long been sought in comparative analyses of brain size relative to body size (herein termed ‘brain size’) in our fellow homeothermic vertebrates – namely other mammals and birds. Unfortunately, brain size is an idiosyncratic trait corresponding to a seemingly miscellaneous collection of traits ranging from gestation length to deception behaviour. Some order can be established by attributing (...) brain size correlates to categories of constraint (‘what traits permit or limit increased brain sizes?’) and selection (‘what traits select for increased brain sizes?. Even so, the vast number of potential correlates has lead to a plethora of (frequently mutually exclusive) hypotheses regarding avian and mammalian brain size evolution. This confusion has recently prompted calls for better integration of brain size correlates. In this article we argue that the latest advances in the field of brain size constraints, combined with modern techniques for tracing brain development, put an integrated framework of brain size evolution within our reach. (shrink)