Kenneth and Mamie Clark studied how racial segregation affected Black children and found that many Black children preferred white dolls, showing the psychological effects of segregation. Their research was used as evidence in Brown v. Board of Education, helping demonstrate the harmful effects of segregation. Lillian Gilbreth used psychology and efficiency research to improve workplaces and everyday products, including kitchen designs, refrigerator shelves, and the foot-pedal trash can. Her work helped develop modern industrial-organizational psychology. William Marston studied the relationship between emotions, blood pressure, and lying, helping develop an early form of the lie detector. He also created Wonder Woman, combining his psychological interests with popular culture.