The Hawthorne studies conducted experiments at the Hawthorne Works factory from 1924-1932 to understand the impact of human relations on productivity. The studies included illumination tests, relay assembly tests, a mass interview program involving 20,000 employees, and a bank wiring observation study. The results showed that social and psychological factors like freedom of expression, participation in decision making, and good communication positively impacted worker productivity and satisfaction more than physical working conditions alone.