Final answer:
Carl Rogers developed scales for measuring empathy, genuineness, and respect, essential elements of his client-centered therapy approach.
Step-by-step explanation:
The individual who developed scales for measuring empathy, genuineness, and respect was Carl Rogers. Rogers was an American psychologist and one of the founders of humanistic psychology. He applied a therapeutic technique called client-centered therapy, which emphasized the therapist's provision of unconditional positive regard, empathy, and genuineness. These conditions were considered essential for helping clients deal with their problems effectively. In contrast, other noted psychologists such as Abraham Maslow are best known for different contributions, like Maslow's hierarchy of needs, and therefore are not the correct answer to this question.