Jeffrey P. Schloss received his undergraduate training in philosophy at University of the Pacific and in biology at Wheaton College. He pursued post baccalaureate training in ecology and evolutionary biology at University of Virginia, University of Michigan, and Washington University, where he received a Ph.D. in 1983. He has taught at the University of Michigan, Wheaton College, Jaguar Creek Rainforest Research Station, and Westmont College, where he is currently Professor of Biology. He also serves as Director of Biological Programs for the Christian Environmental Association and science consultant for the Christian College Coalition Faculty Development Program in Faith & Learning. He has been a Danforth Fellow, a AAAS Fellow in Science Communication and a Fellow of the Discovery Institute. His dual research interests include ecophysiological adaptions of poikilohydric plants to forest microclimate, and sociobiological theories of human altruism and religious faith.

Biological altruism, behavior that results in the reduction of an individual’s fitness while enhancing that of another, has been widely regarded as a central theoretical issue in evolutionary biology, since natural selection should not favor the establishment, much less the stable maintenance of such traits. The issue is central not just to biology. For although selection theory is directly concerned with reproductive consequences and not psychological motivation, insofar as we seek to understand fundamental cognitive and emotional processes in connection with adaptive outcomes, evolutionary explanations of altruism rightly constitute a fundamental issue not only for biology, but for perspectives on human love in the behavioral sciences, and indeed, in philosophy and theology as well.

Over the last century evolutionary explanations of altruism have tended to take three, on the face of it, contrasting approaches. First, individual benefit perspectives have explained apparent reproductive sacrifice in terms of a behavior’s ability to confer direct but not always obvious benefits through sexual selection, kin selection, or reciprocity, or indirectly through reputational enhancement and concomitant access to resources and social services. Most recently, costly signaling and self-deception theories have suggested controversial but illuminating ways of interpreting linkages between sacrificial motivations and the possibility of reputationally-mediated fitness outcomes.

Second, multi-level selection theory has emphasized selection as a hierarchical process operating on several levels of scale. Group selection theory has suggested that integrity of group functioning may be enhanced by, and intergroup adaptive variability may compensate for, intra-group individual reproductive sacrifice. While traditional group selection examines the impact on biological fitness of selection working at supraorganismal levels, several hierarchical or coevolutionary approaches to multilevel selection look at selection working on supraorganismal levels (e.g., memes or other units of cultural transmission).

Third, there are a variety of non-adaptationist approaches to understanding altruism. Altruism in particular, and moral and religious behavior in general, have been suggested to represent incidental, unselected for outcomes of pleiotropic or epigenetic interactions. Positing even more autonomy from biological influence, traditional social science models and some emerging memetic perspectives view the content of culture and the process of its transmission, as dualistically unhinged from the evolutionary process which gave rise to it. Thus human behavior is not just phenotypically plastic within broadly selected constraints, but it transcends such constraint and can freely subvert the agenda of reproductive self-interest. In its most extreme form, this is not an acknwlegement of adaptive limitation or suboptimality but an assertion of uncoupling.

While both the propositions and the personalities associated with the above approaches are frequently represented as irreconcilably contrasting, when divested of polemics they can be understood as congruent in many aspects. Moreover, the ways in which they remain discrete, even oppositional, do not necessarily entail exclusion from simultaneous occurrence. In fact, it is likely that different processes do operate together, thus generating the possibility of different kinds of altruism and apparent altruism. The decontructive potency of individual benefit theory helpfully dereifies glib affirmations of biological transcendence, while the nested complexity of hierarchical theory highlights ways in which human altruistic behavior is appropriately viewed as marvelously unique.

Still, the previous suite of approaches leaves us with unanswered questions in three fundamental areas requiring further research.

First, individual and group selection theories do an excellent job of illuminating the adaptive advantage of intragroup prosocial behavior and even unreciprocated intragroup sacrifice. But the most radical forms of human altruism - extreme sacrifice for nongroup members or enemies where direct reproductive and indirect reputational outcomes are dramatically negative - calls for continuing attention, as does the cross-cultural testimony, not by rhetoricians but practitioners, that such a life strategy is deeply fulfilling or internally rewarding. There are a variety of possible interpretations of such behaviors and the reward structures that may or may not underlie them. But our present ability to determine whether adaptationist or nonadaptationist explanations are warranted, is limited by the methodological difficulty of a) devising developmentally meaningful categorizations of behavioral phenotypes and evaluating the actual fitness outcomes of variance in these phenotypes and b) determining, even if we find a class of behaviors that is fitness reducing, the net adaptive impact across the landscape of allelic combinations and environmental variability (i.e., is the altruistic behavior a hypertrophic version of a trait that more commonly “pays off”?).

Second, most attempts to understand prosociality as an evolutionary adaptation have understandably focused on the impact of such behaviors on manipulating the exchange ratio of physical or cooperative resources. This is a necessary but not sufficient component of the analysis, and to this must be added an elucidation of the distinctly organismal functions generating varying returns on resources, through differences in developmental and homeostatic processes. Just as transpirational water budgets do not seamlessly translate into productivity apart from differences in photosynthetic pathway, so we need to understand how differences in interactive strategy not only result from but themselves influence cognitive and emotional processes in ways which may in turn influence organismal function and homeostasis. Specifically, what is the impact of self relinquishment on measures of well-being? I will suggest several scenaria for positive and negative impacts, in need of empirical resolution.

Third, and most complicated, is the fact that in both longstanding theological and philosophical tradition and in emerging scientific theories, we seek but still lack a coherent view of multilevel phenomena that avoids the explanatory culdesacs of reductive monism and non-interactive dualism. Several versions of coevolutionary and memetic theory, for example, posit mechanisms for the origin, variation, and differential transmission of cultural entities by selective processes that operate at both a higher frequency and higher level of scale than genetic selection. The problem of how they are both embedded in and yet not wholly constrained by genetic selection is not dissimilar to the classic theological question of embodiment (which stands, by the way, in stark contrast to radically dualistic views of personhood). What is needed in our understanding of coevolving cultural entities, especially those underlying altruism, is not just a view of how they ultimately influence and are influenced by genetic adaptations for reproductive fitness - but how this relationship is proximally mediated by preferences, desires, and internal states within the person, and how cultural context may itself influence preferences. With respect to human altruism specifically, there can be little doubt that valorous self relinquishment emerges from our primary biological architecture, and clearly may be adaptive when directed toward mates, progeny, kin, or cooperative guild. What is still a puzzle, is how cultural interaction with volitional preference may direct self-relinquishment toward other ends, including strangers, enemies, nonhuman organisms, landscapes, artifacts, or even nonphysical ideas. I close with several proposals for nature of this transition.