Psychologist: Identical twins are virtually the same genetically. Moreover, according to some studies, identical twins separated at birth and brought up in vastly different environments show a strong tendency to report similar ethical beliefs, dress in the same way, and have similar careers. Thus, many of our inclinations must be genetic in origin, and not subject to environmental influences. Which one of the following, if true, would most weaken the psychologist's argument? ['Scientists are far from being able to link any specific genes to specific inclinations.', 'Many people, including identical twins, undergo radical changes in their lifestyles at some point in their lives.', 'While some studies of identical twins separated at birth reveal a high percentage of similar personality traits, they also show a few differences.', 'Identical twins who grow up together tend to develop different beliefs, tastes, and careers in order to differentiate themselves from each other.']