ABSTRACT
The application of evolutionary theory to the study of social behavior often involves deductive and inductive reasoning. Scientific inquiry employs inductive reasoning, which produces general conclusions from premises about specific cases and in which the premises imply the conclusion with various degrees of certainty. The sociobiological revolution was valuable in at least two ways. First, it offered theoretical rejuvenation to ethology. Second, its empirical findings showed us that behavior of individual animals often is much more finely tuned to specific circumstances than previously would have been believed. Data on fecundity, or timing of estrus, of mothers that raised male versus female offspring in the previous year are good measures of the relative costs of sons and daughters, but, like growth rate data, they say nothing about who controls the exchange of energy. Also, sex differences in growth rates do not necessarily imply differences in maternal investment; they might be due to differences in activity budgets of male and female offspring.
