Dr. weber conducted a long-term study in which people were tested on happiness, asked to make two new friends, and then tested on happiness 1 month later. he noticed that six of the most introverted people dropped out by the last session. therefore, his study might have which of the following internal validity threats?

Mariana would like to include a reference to a journal article in her research paper. which reference is presented in the correct format and contains the needed information? lifestyle changes that impact obesity. national journal of health. campos d. peer reviewed by gotlieb h. and ramirez m. march 2012; 10: 7-10. campos d. lifestyle changes that impact obesity. national journal of health. march 2012; 10: 7-10. campos d. lifestyle changes that impact obesity. national journal of health. peer reviewed by gotlieb h. and ramirez m.. march 2012; 10: 7-10. lifestyle changes that impact obesity. national journal of health. campos d. march 2012; 10: 7-10.