Grand Challenges of Evolutionary Psychology

SHARED CHALLENGES Researchers in evolutionary psychology face the same grand challenges as researchers who eschew the evolutionary approach in their own fi elds of study. Why, and when, do people behave altruistically? How do people make decisions, economic or otherwise, and what role do emotions play in decisionmaking? How do people choose their mates? How do people acquire information, from basic physical knowledge about objects and forces to important local knowledge about particular people and artifacts? How do these processes differ from – or resemble – learning processes among non-humans? How do the answers to all of these questions depend on properties of the individual, such as sex, life history phase, genetic endowment, developmental history, and context? And what are the physiological and neurophysiological substrates of the mechanisms that underlie all of these processes? Evolutionary psychologists share these challenges with researchers from other disciplines because the fi eld is not, of course, distinguished from others in terms of the domain of inquiry. Evolutionary psychologists study economic decision making (like economists), interpersonal and group dynamics (like social psychologists), cultural processes (like anthropologists), and endocrine effects (like physiologists). The questions evolutionary psychologists ask are not only our questions, and the methodological hurdles we must overcome are faced by our colleagues with nonevolutionary approaches because we share the same toolkit, from ethnography to behavioral lab studies to neuroimaging. What, then, are the challenges uniquely faced by evolutionary psychology?


SHARED CHALLENGES
Researchers in evolutionary psychology face the same grand challenges as researchers who eschew the evolutionary approach in their own fi elds of study. Why, and when, do people behave altruistically? How do people make decisions, economic or otherwise, and what role do emotions play in decisionmaking? How do people choose their mates? How do people acquire information, from basic physical knowledge about objects and forces to important local knowledge about particular people and artifacts? How do these processes differ from -or resemblelearning processes among non-humans? How do the answers to all of these questions depend on properties of the individual, such as sex, life history phase, genetic endowment, developmental history, and context? And what are the physiological and neurophysiological substrates of the mechanisms that underlie all of these processes? Evolutionary psychologists share these challenges with researchers from other disciplines because the fi eld is not, of course, distinguished from others in terms of the domain of inquiry. Evolutionary psychologists study economic decision making (like economists), interpersonal and group dynamics (like social psychologists), cultural processes (like anthropologists), and endocrine effects (like physiologists).
The questions evolutionary psychologists ask are not only our questions, and the methodological hurdles we must overcome are faced by our colleagues with nonevolutionary approaches because we share the same toolkit, from ethnography to behavioral lab studies to neuroimaging.
What, then, are the challenges uniquely faced by evolutionary psychology?

UNIQUE CHALLENGES
I would argue that perhaps the fi eld's greatest challenge lies less is coaxing nature to give up her secrets, and more in communicating the insights from evolutionary psychology to those outside the fi eld.
Taking an evolutionary approach has elicited hostility from audiences since the fi eld's inception. The story has frequently been told of the pitcher of water dumped on E.O. Wilson's head at a meeting for the American Association for the Advancement of Science in 1978 (Segerstråle, 2000). This incident can be seen in retrospect as a harbinger of things to come. While the water pitcher has been replaced by the written word, the level of discourse has not always improved. In addition to the political attacks on the fi eld, whether from the left or the right (Segerstråle, 2000;Pinker, 2002), the scientifi c attacks are so strong that they include the charge that evolutionary psychology isn't even a science (Tattersall, 2001).
Indeed, antipathy for the view that doing psychology can be improved with the idea of evolved function has spawned an array of articles and books with more or less provocative titles, including allusions to the "Sins of Evolutionary Psychology" (Panksepp and Panksepp, 2000), a collection of Arguments Against Evolutionary Psychology (Rose and Rose, 2000), Richardson's (2007) Evolutionary Psychology as Maladapted Psychology, and so on.
Antagonism to the fi eld takes the form of a deep skepticism about work that derives from its principles. Kenrick et al. (2005) report an anecdote in which a textbook author found that reviewers insisted he present criticisms of evolutionary research, but not of non-evolutionary research backed by less evidence. Conway and Schaller (2002) made similar observations, suggesting that it is in the context of evolutionary ideas that have consistently been subjected to and resisted falsifi cation "that charges of nonfalsifi ability and other declarations of disbelief are most often aired" (p. 154).
Indeed, the skepticism faced by evolutionary psychological hypotheses is stunning set against the credulousness with which other ideas are greeted. Baumeister and colleagues (e.g., Baumeister et al., 2007) have been advancing an Eighteenth century, pre-enlightenment notion that there is such a thing as "mental energy;" psychology's own phlogiston (c.f., Van den Berg, 1986). This idea is absurd in the context of the computational theory of mind, but its absurdity does not seem to have slowed the pace of publication. From this, it can be inferred that ideas in psychology, even if they are fundamentally incompatible with known facts, don't arouse such skepticism as long as the idea don't derive from a systematic analysis of evolved function. Daly and Wilson (2007) suggest that critics of the fi eld "are not just skeptical, they are angry" (p. 396), and that the skepticism of their research agenda "appears to be motivated by something other than a humble search for the truth" (p. 390). Critics' anger translates into practices that ought to evoke scientifi c outrage. To take just one of many possible examples, Thornhill and Palmer (2000) wrote that "whether rape is an adaption or byproduct cannot yet be defi nitively answered" (p. 84), but their position has been consistently portrayed as the opposite, as Lloyd's (2001) claim that they "begin by assuming that rape is a single trait, and that this trait is an adaptation" (p. 1542, emphasis original). A decade on, editors continue to allow authors to perpetuate this misrepresentation: Leiter and Weisberg (2010, p. 72) recently did so, ironically enough in the context of taking another author to task for misrepresentation 1 .

THE CHALLENGE OF THE CHALLENGES
Debate and discussion are, of course, all to the good. Confl ict helps distill truth, as champions make their cases for their favored proposition, allowing their views to be judged by observers.
in the non-human animal literature (Alcock, 2001); however, this productive framing of discussions can only occur after the relevant scholars have fully understood the logic of adaptationism and its role in hypothesis construction and testing (Cosmides and Tooby, 1997).
This short piece is not the place to wonder why the central animating idea of the fi eld -that the components of the mind have functions -is taken to mean that development occurs without any infl uence of the environment. Alcock (2001) remarked that "the myth of the determinist sociobiologist has been carried forward by some opponents who avoid acknowledging even in passing the long history of rebuttal to this caricature. Why? Because the genetic determinist is too convenient a strawman to be discarded" (p. 44).
A singular challenge is to make progress despite the fact that critics do not appear to have any interest in discarding this convenient strawman.

MOVING FORWARD
The key challenge evolutionary psychologists face is how to interact with the scientifi c community in a way that does not elicit the usual errors described above. This is not, of course, to say that evolutionary psychologists are always right or that any given functional hypothesis will turn out to be correct. Evolutionary psychologists, like other social scientists -or any scientists for that matter -are obviously going to be wrong with great frequency. Favored hypotheses will turn out to be incorrect, errors in reasoning will become clear, and lines of research will have to be reevaluated and abandoned.
As things currently stand, however, the typical process of correction is retarded because interlocutors with evolutionary psychology ignore the dialectic of science.
Instead of challenging ideas and hypotheses, critics challenge assumptions and commitments no one holds.
This suggests that the real challenge for evolutionary psychology is to get others to challenge them on scientifi c grounds. People who disagree with evolutionary psychologists are welcome; competition and considered debate will only make the fi eld better.
Having said that, and in stark contrast, challenging the just-so story-telling ghouls and genetic determinist ghosts so many hallucinate helps no one.
As long as disagreements are honest, respectful, and about genuine points of confl ict, there really is only one challenge that matters: explaining human behavior.
The challenge faced by evolutionary psychology, however, is that the critics do not participate in this dialectic. Interlocutors engaging with evolutionary psychologists frequently don't engage with evolutionary psychology, preferring instead to fabricate evolutionary psychologists' views, and then attack the imagined positions (see Kurzban, 2002).
Why is this the case? At this point it is unclear. A recent survey potentially illustrates one aspect of the problem. Park (2007) investigated 10 social psychology texts' presentation of Hamilton's (1964) theory of kin selection. This is a good test case because kin selection is central to modern evolutionary biology and directly relevant to human social behavior (family and altruism), and, at least in its broad strokes, is not particularly diffi cult to master, deriving from one inequality with three terms (C < rB). Park reviewed 10 texts. Of the 10, 0 got it right. As Park put it: "Rather than presenting purely scientifi c theories of evolution and kin selection, many textbooks seemed to be presenting a mixture of theory and intuition" (p. 868). If kin selection cannot be conveyed at an undergraduate textbook level, it is perhaps not surprising that more complex ideas have not been suffi ciently well understood by the fi eld's critics to enable them to engage properly.
Indeed, two areas of confusion that stand out. The fi rst area is adaptationism (Williams, 1966). As many people have explained, adaptationism links evidence and hypotheses, relating observations -behavior, morphology, etc. -to hypotheses of evolved function (e.g., Tooby and Cosmides, 1992). The failure to understand the logic of adaptationism -about how hypotheses about function require evidence of design -probably gives rise to worries about "just-so story-telling" (Gould, 1997) and related worries about epistemology (see Ketelaar and Ellis, 2000). Similarly, many critics continue to think, perhaps misled by the word "evolutionary" in the fi eld's moniker, that evolutionary psychologists' hypotheses are about phylogeny, or evolutionary history (e.g., Leiter and Weisberg, 2010, pp. 38-39). Because the logic of adaptationism is central to the discipline, critics' failures to understand it represents a signifi cant impediment to progress.
Indeed, substantial progress will have been made when debates focus on putative functions of computational mechanisms, as