BookBlog

The thesis of Cats Paws and Catapults is an argument against naive biomimicry. There is a fashionable and romantic belief that natural design is “better” than manmade technology, and human technologists should therefore borrow designs from nature.
The clearest counterarguments Steven Vogel brings are about locomotion by air and water. The attempt to use birds as a model for human flight set inventors off in the wrong direction. Birds are smaller than people, and so the characteristics of their flight technology is different. Larger entities need to go faster to stay aloft. Propellers and jets are superior to flapping wings for heavy humans; lighter birds don’t need the speed. Similarly, marine creatures are smaller than ships. Waves pose a significant barrier for smaller, lighter swimmers, so most marine locomotion happens beneath the surface of the water. Characteristics change yet again at smaller sizes; some insects like water striders are just the right size to take advantage of surface tension.
“Cat’s Paws” compares and contrasts human technology with natural technology in a range of domains: structure, shape, materials, locomotion, using lots of examples from the worlds of biology and artifact. Vogel explains the physical principles, benefits and tradeoffs for the different design approaches, using words to describe the basic math. The material would be even more fun and memorable with animated calculators that showed the changing properties of flight, structural support, and so on, allowing participants to see the impact of changing values. I wonder if this simulation exists somewhere.
The argument is made with a light hand, and the bulk of the book consists of delightful comparisons and contrasts between very different ways of solving design problems. When it comes to biomimicry, Vogel argues the most effective examples involve borrowing some aspects of a natural design, such as a dolphin’s streamlined shape inspiring aerodynamic vehicles, a beetle’s jaws inspiring chainsaw teeth, and the adhesive characteristics of burr inspiring velcro. The models are adapted from nature to the specific design problem and materials needed for the human requirement.
The critique of naive biomimicry focuses largely on the operating characteristics of the technologies: how they solve the presenting design problems of structure and motion. In doing so, Vogel misses a few key points about how and why human designers might want to emulate nature.
Vogel explains that human technology is able to leverage much higher temperatures and temperature ranges than natural technologies. The book, published in 1997, takes for granted the enormous amounts of seemingly cheap fossil fuel energy that allows humans to run our blast furnaces and jet engines. Sample throwaway quote: “One must remember that, their image makers notwithstanding, utility companies are in the business to sell, not save power.” (California fixed this in 1982, when the state Public Utilities Commission came up with the decoupling idea that would allow utility profits to grow while sales declined.)
Another topic that the book doesn’t address at all is waste. Human production processes have tended to create vast quantities of frequently harmful waste; smog, nonbiodegradable plastics, heavy metals in rivers, fertilizer-created dead zones in oceans. Natural processes tend to consume byproducts instead of creating waste, perhaps because they evolved at slower scale in the context of ecosystems, and perhaps because of accidents of chemistry. Birds digest fruit pulp and excrete the seeds that grow another plant. Animals at the end of their life become food for vultures, larvae, and bacteria.
To date, human industrial technologies have been hugely wasteful of energy and materials. Our culture needs more sustainable processes, not because it sounds romantic but because the current solutions won’t last. Vogel’s insight that natural models are best adapted, not borrowed, can be seen in industrial parks that use the byproducts of one manufacturing process as the feedstocks for another, and the use of microbes to detoxify industrial waste.
There are other areas where science and technology have gone beyond the information available to Vogel when he wrote the book a decade ago. Human artifacts are assembled or processed, while natural artifacts are grown. The growth process consists of an development process that creates the organism, and the ongoing chemical processes that sustain the organism; both sets of processes governed by genetic programs. Human products are often assembled at the macroscopic level, while biological products are assembled at the molecular and cellular levels. It would be interesting now, and probably even more interesting ten or twenty years from now, to read a version of the book taking into account insights and progress in the areas of gene-driven development and nanotechnology.

Recently read two books by physicians with different angles on the same topic: how doctors make mistakes. Jerome Groopman is an oncologist who writes in how Doctors Think about the prejudices, biases, and cognitive errors that result in missed diagnoses. Doctors make mistakes when they dislike their patients, when they like patients to much, when they fail to listen to patients enough; when they see the common and miss the unusual, when they are in love with their own expertise. Groopman focuses on the personal and interpersonal, the nuances the doctor-patient relationship and the thought processes in the doctor’s mind.
Atul Gawande is a surgeon who focuses in Better on system problems and process solutions; methods for mass immunization, saving the lives of wounded soldiers, combatting hospital infection, and extending the lives of cystic fibrosis patients. The two doctors advocate different paths to improvement; Gawande encourages increased measurement, system improvement, and standardization; Groopman encourages personal reflection and better communication with patients, and is distrustful (with evidence) of computer-aided protocols that lead doctors to override their better judgment.
While the two physicians have different takes on how to reduce mistakes, they seem both to be a part of an underlying shift in how doctors respond to mistakes. A desire to maintain authority and prevent liability discouraged doctors from acknowledging mistakes. The newer mindset sees that analyzing mistakes with a focus on learning rather than blame can help prevent more errors.
Both doctors criticize the impact of “managed care” on the quality of medicine. Groopman writes about how doctors are encouraged to rush, eliminating doctor-patient relationships, and how drug company perks affect doctors’ judgement. Gawande describes how insurance-company protocols are designed to reduce reimbursement rather than to improve care. Incentives in the US health care system for quality, cost, and accountability are not complementary. We keep paying more and get better technology but not on the whole better care.

Why do caterpillars hang from trees? They bungee jump from a silk thread in order to flee a hungry bird or other threat. They can crawl back up the thread or descend to the ground. How do beavers build their dams and lodges? With great variety and flexibility, never the same way twice, depending on the weather, landscape, population, and other factors. Animal Architects discusses insect silk, beaver dams, birds nests, bee hives, and other examples of animal building. The stories are fascinating in themselves, and the thesis is tells a larger story. The authors use numerous examples, from stereotyped wasp nests, to the highly flexible building strategies of beavers, to build taxonomies of mapping, from stimulus-response to concept-building, and social intelligence, from isolation to multi-dimensional decision-making. The picture of animal intelligence is much richer and more nuanced than the “stimulus-response” behaviorist school.
There is a strong perceived dichotomy between “intelligence” and “instinct”. It can be seen in today’s article Washington Post article about a recent scientific study showing that humans pleasure centers are stimulated by acts of generosity and kindness. The article quotes neuroscientists and philosophers suggesting that these scientific studies take moral judgements outside of the realm of morality and into the domain of physical determinism. “Joshua D. Greene, a Harvard neuroscientist and philosopher, said multiple experiments suggest that morality arises from basic brain activities. Morality, he said, is not a brain function elevated above our baser impulses. Greene said it is not “handed down” by philosophers and clergy, but “handed up,” an outgrowth of the brain’s basic propensities.” But the expression of morality – like other aspects of human behavior — intertwines instincts, emotions, culture, and reason. The interesting thing isn’t nature or nurture, it’s the fascinating combinations.