Distinctions can be made between ultimate questions and answers, that is, questions and answers in which a longer-term, evolutionary perspective is taken, and proximate questions and answers, that is, questions and responses that look at the more immediate processes. Skinner would argue that his research interest was largely in proximate questions and answers, that is, in selection processes that occurred in the organism's lifetime (the contingencies of reinforcement). However, he would also argue that these would need to be set in an ultimate context, provided by the contingencies of survival.
丹念な進化論的考察によるさまざまな疑問とその答えと、単に目に見える目前の過程に対する疑問とその答えとは、きちんと区別すべきである。スキナーは、生活体の生涯にわたる淘汰過程（強化随伴性)、すなわち、狭い範囲の疑問とその答えに関心を持ち研究したが、それを適者生存の随伴性に基礎を置き、種の生存という視点で考察すべきだと主張した。