With Tinbergen’s four questions in mind (II), we can continue examining the reasons why evolution might be irrelevant for the study of a particular trait, even though the trait is a product of evolution. Reason #4 has already been considered (I) and this post will consider reason # 3:
The concept of design long predates the concept of evolution. The fact that an object or process is well designed for a purpose can be established without knowing about the designing process. An insect that mimics a leaf is well designed to avoid detection by predators. Who cares if it is a product of evolution or a supernatural agent?
Reasoning on the basis of design is so powerful, and we are intuitively so good at it, that it is a likely candidate for a genetically evolved adaptation. We employ it all the time in everyday life, especially when interpreting each other’s behavior. We also employ it erroneously all the time, as when we agonize over why a natural disaster happened, as if there must be a reason beyond purely physical causes. Belief in supernatural agents is often attributed to our wanton tendency to think in terms of agency, even when it isn’t justified.
If we have correctly inferred the purpose of an object, process, or agent, then we can proceed to reason about it intuitively without explicit reference to evolution as the designing process–but that’s a big “if”! If we have inferred the wrong purpose or if there isn’t a purpose, then we have embarked on a long road to nowhere and it’s not easy to find our way back.
It is helpful to remember the history of creationism as an example of design thinking gone wrong. Creationists regarded the natural world as suffused with purpose and design, based on the concept of a benign creator. Their theory of the designing process enabled them to make correct inferences about design some of the time (e.g., the heart functions as a pump) but not others (e.g., apparent cruelty in nature has a benign purpose, even though it is inscrutable to us). Darwin’s theory of evolution was revolutionary precisely because if offered a different conception of the designing process, which made a big difference in the interpretation of design. Darwin’s theory made sense of both the previously correct inferences (e.g., about the heart functioning as a pump), and resolved the previous paradoxes (e.g., cruelty is an expected outcome of natural selection).
The need to know about the designing process to correctly infer the presence and absence of design is a complicated business, even for the evolutionist. The design of sexual ornaments was a puzzle for Darwin until he formulated the concept of sexual selection. Creationist theories assumed that nature is well designed at all levels–for groups, species, and ecosystems no less than individuals. It has taken a long time for evolutionists to establish that design should be expected at a given level only when special conditions are met–and that these conditions sometimes fail at the individual level (e.g., intragenomic conflict). Then there is the concept of mismatch, in which design can only be understood in reference to a past but not the present environment. The fact that evolution is a historical process gives biological design a Rube Goldberg quality, unlike what a god or an engineer might create. Even examples of biological design that strike us obvious today, such as the beaks of the finches on the Galapagos Islands, required decades of hard work to establish as adaptations that evolved by natural selection. The so-called “Adaptation War” that Stephen Jay Gould and Richard Lewontin started with their famous “Spandrels” paper was all about correct and incorrect uses of design thinking within evolutionary biology.
Against this background, it’s monstrous to think that intuitive design thinking is good enough for the study of human-related subjects. Even without the pitfalls associated with creationism, secular theories of human action are littered with false inferences about design that have led down long roads to nowhere, from which we still need to recover. Here are a few examples that have emerged from Evolution Institute workshops.
• It is common to assume that individuals strive to maximize their absolute welfare in some sense, which is formalized as the maximization of self-regarding preferences in rational choice theory. In contrast, evolution is all about the maximization of relative fitness. Sometimes the maximization of absolute and relative fitness coincide, but at other times they diverge in a way that is highly consequential for public policy formulation, as the economist Robert Frank examines in his forthcoming book The Darwin Economy.
• The metaphor of the invisible hand makes it appear that the maximization of individual welfare straightforwardly leads to the maximization of societal welfare. Nothing could be further from the truth from the standpoint of multilevel selection theory (see this previous post for more).
• Rational choice theory makes assumptions about human preferences and reasoning abilities that are patently false. In the 1950′s, Milton Friedman argued that humans behave as if these assumptions are true, in the same way that trees maximize the exposure of their leaves to light and expert pool players make their shots. Friedman’s “as if” argument sustained rational choice theory for the ensuing decades but it is a supremely naïve version of adaptationism from an evolutionary perspective (see this previous post for more).
• Seemingly self-destructive behaviors in teenagers are often interpreted as pathological in all respects. They might indeed qualify as pathological with respect to long-term individual and societal welfare, but still quality as adaptive with respect to the short-term maximization of relative fitness in harsh environments. This realization makes a large difference for the formulation of effective prevention strategies.
• Educational policies such as age segregation, the restriction of play and physical movement to allow more time for studying, and no touch rules to avoid sexual harassment, all have a surface logic. If they didn’t make sense against the background of certain assumptions, no one would be tempted to formulate them. Yet, the background assumptions are frequently at odds with the way our species is adapted to live in social groups and to transmit large amounts of culturally acquired information.
For each of these examples, inferences about design conflict with evolutionary inferences about design at an elementary level. We’re not talking about advanced discoveries of evolutionary science, which also have much to contribute. We’re talking about basic literacy. A mistaken inference at the elementary level is like embarking on a long road to nowhere, just like creationism.
To conclude, a correct inference about design enables one to proceed without explicitly thinking about evolution as the designing process. For any sizeable human-related subject, we need evolutionary science to make correct inferences about design.