I believe the answer is: Cognitive
The cognitive approach of psychology focuses on how the thought that people have would affect their overall behaviour. The thought process would influence whether people see their problems in positive or negative lights. People who see them in negative perspective, tend to adopt a defeatist behaviour and tend to choose to run away from their problems rather than facing it.
Dr. Jackson has spent a lifetime studying how adults solve problems. It is likely that dr. Jackson specializes in the cognitive approach to psychology.
