Testing tiny minds
Nineteenth-century Western scientists inherited the notion that a strict line separated humans from other animals. Humans had souls, which came with complex thoughts and feelings, and other creatures didn’t. Charles Darwin’s theory of evolution disaffirmed this accepted wisdom, proposing a mechanism — natural selection of inherited traits — by which physical, mental and even emotional characteristics could be shared across species. Darwin’s young friend and collaborator George Romanes in 1882 published Animal Intelligence, a book that cataloged examples of cognitive abilities in a broad spectrum of animals. These ideas resonated so strongly with Turner that he named his third child Darwin Romanes.
Darwin’s and Romanes’s notions, though, were largely based on theory, observation and a healthy dollop of anthropomorphism. Animal Intelligence was not especially scientific. Turner spent his career testing those notions with the scientific method.
In one of his early studies, Turner set out to investigate if spiders built webs through rigid instinct or if they could respond creatively to novel situations. Meadows make for fairly uniform conditions in which to build webs, he wrote in the Journal of Comparative Neurology in 1892. “But when the external environment becomes more heterogenous, it is interesting to note how the spiders become masters of the situation.” He meticulously described structures of 27 webs he found on windowsills, down railroad embankments, in log piles. “Was this web the result of blind instinct? I think not,” he wrote about an especially contorted web above a hole in a stone wall that effectively cornered insect prey.
Turner coupled his observations with experiments that forced spiders to deal with awkward spatial challenges in their web-building. He collected spiders and placed them first into cylindrical bottles, where they constructed circular webs, and then moved them into boxes, where a few made rectangular ones. Finally, he destroyed parts of existing webs and found that the spiders came up with clever solutions to efficiently patch them up. All these experiments pointed to a capacity for learning, contradicting the dominant scientific narrative. Although web-weaving is instinctive, Turner concluded, “the details of construction are the products of intelligent action.”
During the rest of his three-decade career, Turner continued pursuing research that ran counter to prevailing ideas of his time. Turner also studied birds, aquatic crustaceans, lizards and snakes, but he was particularly interested in the minds of insects. He cataloged surprising capacities for learning, memory, problem-solving — and possibly even emotions, says Chittka — in ants, bees, moths, cockroaches and other insects, anticipating perspectives that only reemerged in the 2000s.