Taken straight from the Ben and Dan franchise page
Dan Marshall is a well-read and fastidious computer programmer. He may look like Indiana Jones
with his brown leather jacket, but he generally lacks any confidence in his adventuring abilities. As a result, Dan typically just lets Ben take the lead, only doing some occasional switch flipping or computer programming when Ben asks it of him. However, when put in a situation where he has to act on his own without Ben, Dan tends to be able to overcome his lack of confidence and adventuring experience and pull through for his friend.