Chapter 7: Development & Modification of Social Behavior

The text explores the hierarchy of biological responses, distinguishing between immediate biochemical reactions, organismic behavioral adjustments, and slower population-level demographic and genetic changes. A key focus is placed on the potential for rapid behavioral evolution, illustrated by microevolutionary experiments with Drosophila and the theoretical impact of high selection pressures on social traits. The author categorizes organisms into evolutionary grades based on learning capacity, ranging from instinct-reflex machines dependent on token stimuli to generalized learners capable of perceiving history. Morphogenetic adaptations are discussed, including caste determination in social insects and phase transformations in locusts, alongside the nongenetic transmission of maternal experience and stress responses in mammals. The intricate relationship between hormones and behavior is examined, highlighting how endocrine systems prime motivational states and how social signals trigger physiological changes, such as the Bruce and Whitten effects in rodents. The chapter challenges the tabula rasa concept by introducing directed learning, where genetic programming biases the acquisition of specific behaviors, exemplified by the critical periods in bird song ontogeny. Socialization is analyzed through the lens of environmental deprivation studies, particularly in rhesus monkeys, revealing the critical roles of maternal and peer interactions in normal development. The function of play is debated, contrasting structuralist and functionalist perspectives while emphasizing its role in skill acquisition and social bonding in higher vertebrates. Finally, the discussion extends to the emergence of tradition and culture in nonhuman animals, documenting instances of tool using, such as termite fishing in chimpanzees, and the cultural transmission of novel behaviors like potato washing in Japanese macaques, which demonstrates how behavioral innovations can spread through populations via imitation and tradition drift.