Industrial-Organizational Psychology (I-O Psychology) focuses on the application of psychological theories and principles to the workplace. It aims to understand and optimize human behavior in organizations. Here are some key concepts, theories, and contributors in I-O psychology:

1. Scientific Management
   • Theorists/Contributors: Frederick Winslow Taylor
   • Description: This theory, also known as Taylorism, analyses and synthesizes workflows to improve efficiency in the workplace.
2. Hawthorne Studies
   • Theorists/Contributors: Elton Mayo
   • Description: These studies demonstrated the effects of social and environmental factors on productivity and morale.
3. Theory X and Theory Y
   • Theorists/Contributors: Douglas McGregor
   • Description: These theories describe two different assumptions about human behavior at work – Theory X assumes people dislike work and Theory Y assumes people are self-directed and find work natural.
4. Job Characteristics Model
   • Theorists/Contributors: J. Richard Hackman and Greg Oldham
   • Description: This model describes how certain job characteristics affect job outcomes and personal preferences.
5. Goal Setting Theory
   • Theorists/Contributors: Edwin A. Locke
   • Description: This theory posits that setting specific and challenging goals leads to higher performance.
6. Equity Theory
   • Theorists/Contributors: John Stacey Adams
   • Description: This theory suggests that employees seek to maintain equity between the inputs they bring to a job and the outcomes they receive.
7. Organizational Culture and Climate
   • Theorists/Contributors: Edgar Schein and others
   • Description: These refer to the shared values, beliefs, and practices in an organization.
8. Transformational Leadership
   • Theorists/Contributors: James V. Downton, James MacGregor Burns, Bernard M. Bass
   • Description: Transformational leadership involves leaders inspiring and motivating employees to innovate and create change.
9. Person-Environment Fit
   • Theorists/Contributors: Various
   • Description: This concept involves the compatibility between individuals and the work environment.
10. 360-Degree Feedback
    • Theorists/Contributors: Various
    • Description: This is a process where employees receive confidential feedback from those who work around them.
11. Occupational Health Psychology
    • Theorists/Contributors: Various
    • Description: This area focuses on practices that promote employee well-being and health.
12. Human Factors and Ergonomics
    • Theorists/Contributors: Various
    • Description: This is an interdisciplinary area that focuses on designing products and systems to fit the people who use them.
13. Talent Management and Employee Development
    • Theorists/Contributors: Various
    • Description: This includes practices designed to attract, develop, engage, and retain productive employees.
14. Five Factor Model of Personality

• Theorists/Contributors: Robert McCrae and Paul Costa
• Description: This model describes five core traits that interact to form human personality: Openness, Conscientiousness, Extraversion, Agreeableness, and Neuroticism.

15. Expectancy Theory

• Theorists/Contributors: Victor Vroom
• Description: This theory explains the process that individuals undergo to make decisions, based on their expectation that a certain outcome will follow their actions.

These concepts and theories form the foundation of Industrial-Organizational psychology, which seeks to apply psychological theories to enhance individual and organizational performance.