Final answer:
Hans Eysenck's critique of psychotherapy had two effects on clinical psychology: questioning the effectiveness of psychotherapy and promoting evidence-based treatments and research.
Step-by-step explanation:
Hans Eysenck's critique had two major effects on the field of clinical psychology. Firstly, it challenged the prevailing view that psychotherapy was effective for all psychological disorders. Secondly, Eysenck's personality theory, which highlights extroversion/introversion and neuroticism/stability dimensions, provided a biological basis for understanding individual differences in personality. His critique and theory promoted the exploration of the genetic and physiological underpinnings of personality and behavior, broadening the scope of psychological research and intervention approaches. This paved the way for further interdisciplinary cooperation among psychology, genetics, and neuroscience, enhancing the development of integrated treatment modalities. Eysenck argued that psychotherapy was no more effective than simply waiting for time to heal. Secondly, his critique sparked an increased focus on evidence-based treatments and the importance of empirical research in clinical psychology.