Introduction:
Studying previous years' papers can indeed help in identifying any shifts in the UPSC's focus on applied psychology and the practical relevance of psychological theories. Analyzing the pattern and content of past papers can provide valuable insights into the changing trends and areas of emphasis in the UPSC examinations.

Identifying shifts in focus:
By closely examining previous years' papers, one can observe the following shifts in the UPSC's focus on applied psychology and the practical relevance of psychological theories:

1. Change in question types: The types of questions asked in the UPSC exams may vary over the years. By studying past papers, one can identify any shifts in the question patterns related to applied psychology. For example, earlier papers may have focused more on theoretical knowledge and basic concepts, while recent papers might include more practical application-based questions.

2. Emerging topics and theories: The study of previous years' papers can help identify any emerging topics or theories that have gained significance in the field of applied psychology. This can include areas such as positive psychology, organizational behavior, or cross-cultural psychology. By analyzing the frequency of questions related to these topics in recent years, one can gauge their importance and relevance in the UPSC exams.

3. Integration of interdisciplinary knowledge: The UPSC exams often require candidates to have a multidisciplinary approach. By studying previous papers, one can determine if there has been an increased emphasis on the integration of psychological theories with other subjects such as sociology, economics, or political science. This can highlight the importance of practical application and relevance of psychological theories in a broader context.

4. Case studies and practical scenarios: Another shift that can be observed through the analysis of previous papers is the inclusion of more case studies and practical scenarios. UPSC may present candidates with real-life situations and ask them to apply psychological theories to analyze and solve problems. By studying past papers, one can identify any increasing trend in such application-based questions.

Conclusion:
Studying previous years' papers can be a valuable strategy to identify any shifts in the UPSC's focus on applied psychology and the practical relevance of psychological theories. By analyzing question patterns, emerging topics, interdisciplinary integration, and the inclusion of practical scenarios, candidates can better prepare themselves for the UPSC examinations. It is important to adapt one's preparation strategy based on the changing trends observed through the study of past papers.