Psychologist Edwin Twitmyer at the University of Pennsylvania in the U.S. discovered classical conditioning at approximately the same time as Pavlov was conducting his research . 1 However, the two were unaware of each other's research in this case of simultaneous discovery, and Pavlov received credit for the findings.
Definition of generation for English Language Learners. : 1  a group of people born and living during the same time. : 2  the people in a family born and living during the same time. : 3  the average length of time between the birth of parents and the birth of their children.
The average generation is the average age of parents at the time of birth of their children. When life span increases, so does the average length of generations.